<PAGE>

                                                                    EXHIBIT 10.8

The securities represented by this certificate have been issued and sold in
reliance upon exemptions from registration under the Securities Act of 1933, as
amended (the "1933 Act"), Section 10-5-9 (13) of the Official Code of Georgia
Annotated (the "Georgia Code") and appropriate exemptions from registration
under the securities laws of other applicable jurisdictions. The securities may
not be offered for sale, sold or transferred other than pursuant to an effective
registration statement or an exemption therefrom satisfactory to the issuer
under the 1933 Act, the Georgia Code and the applicable securities laws of any
other jurisdiction. The issuer shall be entitled to require an opinion of
counsel reasonably satisfactory to it with respect to compliance of the proposed
sale or transfer with the registration requirements of the 1933 Act or an
exemption therefrom.

              SERIES E CONVERTIBLE PREFERRED STOCK PURCHASE WARRANT

Warrant No. PE                                   Number of Shares

                                 INHIBITEX, INC

                          Void after December 19, 2008

         1.       Issuance. This Warrant is issued to __________ (the
"Investor") by Inhibitex, Inc., a Delaware corporation (hereinafter with its
successors called the "Company").

         2.       Purchase Price; Number of Shares. Subject to the terms and
conditions hereinafter set forth, the registered holder of this Warrant (the
"Holder"), commencing on the date hereof, is entitled to purchase from the
Company at a price per share (the "Purchase Price") of $5.91,              fully
paid and nonassessable shares of Series E Convertible Preferred Stock, $.001 par
value, of the Company (the "Series E Preferred Stock"). Until such time as this
Warrant is exercised in full or expires, the Purchase Price and the securities
issuable upon exercise of this Warrant are subject to adjustment as hereinafter
provided.

         3.       Exercise of Warrant. This Warrant may be exercised by the
Holder upon the surrender of this Warrant, with the subscription form annexed
hereto duly executed, at the office of the Company, 1165 Sanctuary Parkway,
Suite 400, Alpharetta, Georgia 30004, or at such other office as the Company
notifies the Holder of in writing, together with payment of the Purchase Price
(or the proportionate part thereof if this Warrant is exercised in part) in the
manner set forth in Section 4 hereof (except in the case of an election under
Section 5 hereof). Upon such surrender of this Warrant, the Company will (a)
issue a certificate or certificates in the name of the Holder for the shares of
the Series E Preferred stock to which the Holder shall be entitled and (b)
deliver to the Holder the proportionate part thereof if this Warrant is
exercised in part, pursuant to the provisions of the Warrant.

         4.       Payment of Purchase Price. The Purchase Price may be paid (i)
in cash or by check, (ii) by the surrender by the Holder to the Company of any
promissory notes or other obligations issued by the Company, with all such notes
and obligations so surrendered being credited against the Purchase Price in an
amount equal to the principal amount thereof plus accrued interest to the date
of surrender, (iii) through delivery by the Holder to the Company of other
securities issued by the Company, with such

<PAGE>

                                      -2-

securities being credited against the Purchase Price in an amount equal to the
fair market value thereof, as determined in good faith by the Board of Directors
of the Company (the "Board"), or (iv) by any combination of the foregoing. The
Board shall promptly respond in writing to an inquiry by the Holder as to the
fair market value of any securities the Holder may wish to deliver to the
Company pursuant to clause (iii) above.

         5.       Net Issue Election. The Holder may elect to receive, without
the payment by the Holder of any additional consideration, shares equal to the
value of this Warrant or any portion hereof by the surrender of this Warrant or
such portion to the Company, with the net issue election notice annexed hereto
duly executed, at the office of the Company. Thereupon, the Company shall issue
to the Holder such number of fully paid and nonassessable shares of Series E
Preferred Stock as is computed using the following formula:

                                   X = Y (A-B)
                                       -------
                                          A

where

                  X =      the number of shares to be issued to the Holder
                  pursuant to this Section 5.

                  Y = the number of shares covered by this Warrant in respect of
                  which the net issue election is made pursuant to this Section
                  5.

                  A = the fair market value of one share of Series E Preferred
                  Stock, as determined in good faith by the Board, as at the
                  time the net issue election is made pursuant to this Section
                  5.

                  B = the Purchase Price in effect under this Warrant at the
                  time the net issue election is made pursuant to this Section
                  5.

The Board shall promptly respond in writing to an inquiry by the Holder as to
the fair market value of one share of Series E Preferred Stock.

         6.       Partial Exercise. This Warrant may be exercised in whole or in
part, and the Holder shall be entitled to receive a new warrant, which shall be
dated as of the date of this Warrant, covering the number of shares in respect
of which this Warrant shall not have been exercised.

         7.       Issuance Date. The person or persons in whose name or names
any certificate representing shares of Series E Preferred Stock is issued
hereunder shall be deemed to have become the holder of record of the shares
represented thereby as at the close of business on the date this Warrant is
exercised with respect to such shares, whether or not the transfer books of the
Company shall be closed.

         8.       Expiration Date; Automatic Exercise. This Warrant shall expire
at the close of business on December 19, 2008, or effective upon the closing of
a firm commitment underwritten public offering of shares of Common Stock in
which (i) the Company receives gross proceeds of at least $50,000,000 before
underwriting discounts, commissions and fees and (ii) the price to the public
for such shares is at least $8.00 per share (appropriately adjusted to reflect
any subdivision, combination or stock dividends or distributions of or with
respect to the Common Stock), whichever is earlier, and shall be void
thereafter. Notwithstanding the foregoing, this Warrant shall automatically be
deemed to be exercised in full

<PAGE>

                                      -3-

pursuant to the provisions of Section 5 hereof, without any further action on
behalf of the Holder, immediately prior to the time this Warrant would otherwise
expire pursuant to the preceding sentence.

         9.       Reserved Shares; Valid Issuance. The Company covenants that it
will at all times from and after the date hereof reserve and keep available such
number of its authorized shares of Series E Preferred Stock and Common Stock,
$.001 par value (the "Common Stock"), free from all preemptive or similar rights
therein, as will be sufficient to permit, respectively, the exercise of this
Warrant in full and the conversion into shares of Common Stock of all shares of
Series E Preferred Stock receivable upon such exercise. The Company further
covenants that such shares as may be issued pursuant to such exercise and
conversion will, upon issuance, be duly and validly issued, fully paid and
nonassessable and free from all taxes, liens and charges with respect to the
issuance thereof.

         10.      Stock Dividends. If after the Original Issue Date (as defined
in Section 15 hereof) the Company shall subdivide the Series E Preferred Stock,
by split-up or otherwise, or combine the Series E Preferred Stock, or issue
additional shares of Series E Preferred Stock in payment of a stock dividend on
the Series E Preferred Stock, the number of shares issuable on the exercise of
this Warrant shall forthwith be proportionately increased in the case of a
subdivision or stock dividend, or proportionately decreased in the case of a
combination, and the Purchase Price shall forthwith be proportionately decreased
in the case of a subdivision or stock dividend, or proportionately increased in
the case of a combination.

         11.      Mergers and Reclassifications. If after the Original Issue
Date there shall be any reclassification, capital reorganization or change of
the Series E Preferred Stock (other than as a result of a subdivision,
combination or stock dividend provided for in Section 10 hereof), or any
consolidation of the Company with, or merger of the Company into, another
corporation or other business organization (other than a consolidation or merger
in which the Company is the continuing corporation and which does not result in
any reclassification or change of the outstanding Series E Preferred Stock), or
any sale or conveyance to another corporation or other business organization of
all or substantially all of the assets of the Company, then, as a condition of
such reclassification, reorganization, change, consolidation, merger, sale or
conveyance, lawful provisions shall be made, and duly executed documents
evidencing the same from the Company or its successor shall be delivered to the
Holder, so that the Holder shall thereafter have the right to purchase, at a
total price not to exceed that payable upon the exercise of this Warrant in
full, the kind and amount of shares of stock and other securities and property
receivable upon such reclassification, reorganization, change, consolidation,
merger, sale or conveyance by a holder of the number of shares of Series E
Preferred Stock which might have been purchased by the Holder immediately prior
to such reclassification, reorganization, change, consolidation, merger, sale or
conveyance (or, if there are no holders of Series E Preferred Stock at such
time, by a holder of the number of shares of Common Stock which might have been
acquired by the Holder immediately prior to such reclassification,
reorganization, change, consolidation, merger, sale or conveyance upon the
exercise of this Warrant in full and the conversion into shares of Common Stock
of all shares of Series E Preferred Stock receivable upon such exercise), and in
any such case appropriate provisions shall be made with respect to the rights
and interest of the Holder to the end that the provisions hereof (including
without limitation, provisions for the adjustment of the Purchase Price and the
number of shares issuable hereunder) shall thereafter be applicable in relation
to any shares of stock or other securities and property thereafter deliverable
upon exercise hereof.

         12.      Fractional Shares. In no event shall any fractional share of
Series E Preferred Stock be issued upon any exercise of this Warrant. If, upon
exercise of this Warrant as an entirety, the Holder would, except as provided in
this Section 12, be entitled to receive a fractional share of Series E

<PAGE>

                                      -4-

Preferred Stock, then the Company shall issue the next higher number of full
shares of Series E Preferred Stock, issuing a full share with respect to such
fractional share.

         13.      Certificate of Adjustment. Whenever the Purchase Price is
adjusted, as herein provided, the Company shall promptly deliver to the Holder a
certificate of the Company's Chief Financial Officer setting forth the Purchase
Price after such adjustment and setting forth a brief statement of the facts
requiring such adjustment.

         14.      Notices of Record Date, Etc. In the event of:

                  (a)      any taking by the Company of a record of the holders
of any class of securities for the purpose of determining the holders thereof
who are entitled to receive any dividend or other distribution, or any right to
subscribe for, purchase or otherwise acquire any shares of stock of any class or
any other securities or property, or to receive any other right,

                  (b)      any reclassification of the capital stock of the
Company, capital reorganization of the Company, consolidation or merger
involving the Company, or sale or conveyance of all or substantially all of its
assets, or

                  (c)      any voluntary or involuntary dissolution, liquidation
or winding-up of the Company,

then and in each such event the Company will mail or cause to be mailed to the
Holder a notice specifying (i) the date on which any such record is to be taken
for the purpose of such dividend, distribution or right, and stating the amount
and character of such dividend, distribution or right, or (ii) the date on which
any such reclassification, reorganization, consolidation, merger, sale or
conveyance, dissolution, liquidation or winding-up is to take place, and the
time, if any is to be fixed, as of which the holders of record in respect of
such event are to be determined. Such notice shall be mailed at least 20 days
prior to the date specified in such notice on which any such action is to be
taken.

         15.      Other Warrants. This Warrant is one of a series of warrants
(collectively, the "Warrants") that were originally issued by the Company on
December 19, 2003 (the "Original Issue Date") pursuant to a Series E Preferred
Stock and Warrant Purchase Agreement dated as of the Original Issue Date by and
among the Company and the other parties thereto.

         16.      Amendment. The terms of this Warrant may be amended, modified
or waived only with the written consent of the Company and the holders of
Warrants representing at least two-thirds of the number of shares of Series E
Preferred Stock then issuable upon the exercise of the Warrants. No such
amendment, modification or waiver shall be effective as to this Warrant unless
the terms of such amendment, modification or waiver shall apply with the same
force and effect to all of the other Warrants then outstanding.

         17.      Warrant Register; Transfers, Etc.

                  A.       The Company will maintain a register containing the
names and addresses of the registered holders of the Warrants. The Holder may
change its address as shown on the warrant register by written notice to the
Company requesting such change. Any notice or written communication required or
permitted to be given to the Holder may be given by certified mail or delivered
to the Holder at its address as shown on the warrant register.

<PAGE>

                                      -5-

                  B.       Subject to compliance with applicable federal and
state securities laws, this Warrant may be transferred by the Holder with
respect to any or all of the shares purchasable hereunder. Upon surrender of
this Warrant to the Company, together with the assignment hereof properly
endorsed, for transfer of this Warrant as an entirety by the Holder, the Company
shall issue a new warrant of the same denomination to the assignee. Upon
surrender of this Warrant to the Company, together with the assignment hereof
properly endorsed, by the Holder for transfer with respect to a portion of the
shares of Series E Preferred Stock purchasable hereunder, the Company shall
issue a new warrant to the assignee, in such denomination as shall be requested
by the Holder hereof, and shall issue to such Holder a new warrant covering the
number of shares in respect of which this Warrant shall not have been
transferred.

                  C.       In case this Warrant shall be mutilated, lost, stolen
or destroyed, the Company shall issue a new warrant of like tenor and
denomination and deliver the same (i) in exchange and substitution for and upon
surrender and cancellation of any mutilated Warrant, or (ii) in lieu of any
Warrant lost, stolen or destroyed, upon receipt of evidence reasonably
satisfactory to the Company of the loss, theft or destruction of such Warrant
(including a reasonably detailed affidavit with respect to the circumstances of
any loss, theft or destruction) and of indemnity reasonably satisfactory to the
Company, provided, however, that so long as Investor is the registered holder of
this Warrant, no indemnity shall be required other than its written agreement to
indemnify the Company against any loss arising from the issuance of such new
warrant.

         18.      No Impairment. The Company will not, by amendment or
restatement of its Seventh Amended and Restated Certificate of Incorporation or
through any reclassification, capital reorganization, consolidation, merger,
sale or conveyance of assets, dissolution, liquidation, issue or sale of
securities or any other voluntary action, avoid or seek to avoid the observance
or performance of any of the terms of this Warrant, but will at all times in
good faith assist in the carrying out of all such terms and in the taking of all
such action as may be necessary or appropriate in order to protect the rights of
the Holder.

         19.      Governing Law. The provisions and terms of this Warrant shall
be governed by and construed in accordance with the internal laws of the State
of Delaware.

         20.      Successors and Assigns. This Warrant shall be binding upon the
Company's successors and assigns and shall inure to the benefit of the Holder's
successors, legal representatives and permitted assigns.

         21.      Business Days. If the last or appointed day for the taking of
any action required or the expiration of any right granted herein shall be a
Saturday or Sunday or a legal holiday in Delaware, then such action may be taken
or right may be exercised on the next succeeding day which is not a Saturday or
Sunday or such a legal holiday.

<PAGE>

                                       -6-

         22.      No Rights as Shareholder. Except as otherwise provided herein
or in the Fourth Amended and Restated Master Rights Agreement dated as of the
date hereof between the Company and the parties listed therein, as amended from
time to time, this Warrant does not confer upon the Holder any right to vote or
to consent to or receive notice as a shareholder of the Company, as such, in
respect of any matters whatsoever, or any other rights or liabilities as a
shareholder, prior to the exercise hereof.

Dated: December __, 2003                    INHIBITEX, INC.

                                            _______________________________

(Corporate Seal)                            By:____________________________

Attest:                                     Title:_________________________

<PAGE>

                                      -7-

                                  Subscription

To:____________________                      Date:_________________________

         The undersigned hereby subscribes for __________ shares of Series E
Preferred Stock covered by this Warrant. The certificate(s) for such shares
shall be issued in the name of the undersigned or as otherwise indicated below:

                                    _________________________________
                                    Signature

                                    _________________________________
                                    Name for Registration

                                    _________________________________
                                    Mailing Address

                            Net Issue Election Notice

To:____________________                      Date:_________________________

         The undersigned hereby elects under Section 5 to surrender the right to
purchase _______ shares of Series E Preferred Stock pursuant to this Warrant.
The certificate(s) for the shares issuable upon such net issue election shall be
issued in the name of the undersigned or as otherwise indicated below.

                                    _________________________________
                                    Signature

                                    _________________________________
                                    Name for Registration

                                    _________________________________
                                    Mailing Address

<PAGE>

                                       -8-

                                   Assignment

         For value received ____________________________ hereby sells,

assigns and transfers unto ______________________________________

___________________________________________________________________________
    Please print or typewrite name and address of Assignee

___________________________________________________________________________

the within Warrant, and does hereby irrevocably constitute and appoint
_______________________ its attorney to transfer the within Warrant on the books
of the within named Company with full power of substitution on the premises.

Dated:_______________________

                                           _____________________________

In the Presence of:

_____________________________