Document:

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                                                                   EXHIBIT 10.16

                  SECOND AMENDMENT TO STOCK PURCHASE AGREEMENT

     THIS SECOND AMENDMENT effective as of May 1, 2000 to the Stock Purchase
Agreement dated as of September 22, 1999 among JAKKS Pacific, Inc., Flying
Colors, Inc. (formerly Colorbok Paper Products, Inc.) and the former
shareholders thereof named therein (the "Agreement").

                              W I T N E S S E T H:
                              - - - - - - - - - - -

     WHEREAS, the Agreement provided for JAKKS and Joshua H. Pokempner
("Pokempner") to enter into an Employment Agreement and contemplated that
Pokempner would remain employed by JAKKS throughout the term provided therein;
and

     WHEREAS, JAKKS and Pokempner entered into the Employment Agreement as of
October 1, 1999 but have, by their mutual consent, terminated Pokempner's
employment by JAKKS effective as of the close of business on April 30, 2000; and

     WHEREAS, the parties to the Agreement desire to amend the Agreement to
permit the termination of Pokempner's employment without affecting the Earn-Out
(as defined in the Agreement) and other provisions of the Agreement;

     NOW, THEREFORE, the parties hereto hereby agree as follows:

     1. The provisions of Sections 2.5(e) and (f) of the Agreement shall not
apply to the termination of Pokempner's employment, which shall not affect the
determination or payment of the Earn-Out as otherwise provided in such Section
2.5.

     2. From and after May 1, 2000, the provisions of Section 2.5(g) of the
Agreement shall not apply to Pokempner.

     3. In all other respects, the Agreement shall continue in full force and
effect.

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     IN WITNESS WHEREOF, the undersigned have duly executed this Second
Amendment as of this 26th day of June, 2000.

                         JAKKS PACIFIC, INC.

                         By:  /s/ JOEL M. BENNETT
                              -------------------------------------------
                              Name:  Joel M. Bennett
                              Title: Executive Vice President

                         FLYING COLORS, INC.

                         By:   /s/ JOEL M. BENNETT
                               --------------------------------------------
                               Name:  Joel M. Bennett
                               Title: Chief Financial Officer

                               /s/ JOSHUA H. POKEMPNER
                         ---------------------------------------------------
                         Joshua H. Pokempner, as Agent as of the Shareholders

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                                                                  EXHIBIT 10.127

                                AMENDMENT NO. 1

        THIS AMENDMENT is entered into the 2nd day of June 2000

BETWEEN:

        (1) AXYS PHARMACEUTICALS, INC., a Delaware Corporation having a
principle place of business at 180 Kimball Way, South San Francisco, CA 94080,
USA ("Axys"); and

        (2) AVENTIS PHARMACEUTICALS PRODUCTS INC. (formerly known as
RHONE-POULENC RORER PHARMACEUTICALS INC.), a Delaware Corporation having a place
of business at 500 Arcola Road, Collegeville, Pennsylvania 19426, USA ("APPI").

RECITALS:

        (A) Under a Collaborative Research and License Agreement dated 11
December 1998 (the "Collaborative Research and License Agreement"), Axys and
APPI agreed to collaborate in the discovery, development and commercialisation
of Cathepsin S inhibitors for use in the prevention and/or treatment of certain
human diseases.

        (B) In Article 6.3(a) of the Collaborative Research and License
Agreement, [*] payments are proposed for each of:

                (i)   first demonstration of [*] in an [*] for any [*];

                (ii)  first satisfaction of the [*] for any [*];

                (iii) first satisfaction of [*] for any [*]; and

                (iv)  first satisfaction of [*] by an [*].

        (C) In the newly-formed pharmaceuticals business of Aventis Pharma,
contemplated in Article 11.2 of the Collaborative Research and License
Agreement, the criteria identified in Recitals (B) [*] above [*], and [*] are
modified.

[*] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY
BRACKETS, HAS BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE
COMMISSION PURSUANT TO RULE 24B-2 OF THE SECURITIES EXCHANGE ACT OF 1934, AS
AMENDED.

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        (D) APPI will continue to honour the [*] payments set out in Article
6.3(a) of the Collaborative Research and License Agreement. This Amendment
formalises the mechanism for payment of the [*] described in Recitals (B) [*]
above, and sets out the [*] in Appendix 1 hereinafter.

        NOW, THEREFORE, IN CONSIDERATION OF THE VARIOUS PROMISES AND
UNDERTAKINGS SET FORTH HEREIN, AXYS AND APPI AGREE AS FOLLOWS:

        1. Words and expressions defined in the Collaborative Research and
License Agreement shall have the same meaning in this Amendment.

        2. Article 6.3 of the Collaborative Research and License Agreement is
hereby amended to re-define the [*] which shall have the meaning set forth in
Appendix 1 hereinafter, unless subsequently further modified by [*]. Any further
changes to the [*] will be communicated to the [*], which will determine in good
faith if any such changes necessitate an amendment to the Collaborative Research
and License Agreement.

        3. Exhibit A, "Phase Transition Criteria", of the Collaborative Research
and License Agreement is hereby amended by the deletion of [*], which section of
Exhibit A shall be restated in its entirety to read in full as set forth in
Appendix 1 hereafter. Determination of the completion of all elements of
Appendix A to trigger the payment described in Recital (B) [*] above will be
made by a decision of the [*], or such other [*] shall hereafter determine.

        4. All elements of [*] and [*] of Exhibit A, "Phase Transition
Criteria", of the Collaborative Research and License Agreement are hereby
retained. Determination of the completion of all such elements to trigger the
payments described in Recitals (B) [*] above will be made by a decision of the
[*] in accordance with the process defined in [*] of the Collaborative Research
and License Agreement.

[*] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY
BRACKETS, HAS BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE
COMMISSION PURSUANT TO RULE 24B-2 OF THE SECURITIES EXCHANGE ACT OF 1934, AS
AMENDED.

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        5. Article 1.2 of the Collaborative Research and License Agreement is
hereby amended and restated to read in full as follows:

        "1.2 "Affiliate" with respect to Axys, shall mean any Person
        controlling, controlled by, or under common control with Axys. With
        respect to APPI, "Affiliate" shall mean any Person controlled by
        Rhone-Poulenc Rorer Inc., a Pennsylvania corporation, or Aventis Pharma
        Holding GmbH or Aventis Pharma AG, both of which are German
        corporations. For purposes of this Section 1.2 only, "control" shall
        refer to (a) the possession, directly or indirectly, of the power to
        direct the management and policies of a Person, whether through the
        ownership of voting securities, by contract or otherwise or (b) the
        ownership, directly or indirectly, of at least 50% (or, if less, the
        maximum ownership interest permitted by law) of the voting securities or
        other ownership interest of a Person."

        6. Article 11.2 of the Collaborative Research and License Agreement is
hereby amended and restated to read in full as follows:

        Except as expressly provided herein, neither this Agreement nor any
        interest hereunder shall be assignable, nor any other obligation
        delegable, by a Party without the prior written consent of the other;
        provided, however, that a Party may assign this Agreement to any
        Affiliate or to any successor in interest by way of merger or sale of
        all or substantially all of its assets in a manner such that the
        assignor shall remain liable and responsible for the performance and
        observance of all such Party's duties and obligations hereunder. This
        Agreement shall be binding upon the successors and permitted assigns of
        the Parties. Any assignment not in accordance with this Section 11.2
        shall be void. On December 15, 1999, Rhone-Poulenc S.A. combined its
        life science businesses with those of Hoechst AG by acquiring all of the
        outstanding voting securities of Hoechst AG through a tender offer (the
        "Merger"). Upon consummation of the Merger, Rhone-Poulenc S.A. renamed
        the combined company Aventis S.A. ("Aventis"). It is the Parties'
        intention that this Agreement shall [*], but not to the [*]. As a result
        of the

[*] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY
BRACKETS, HAS BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE
COMMISSION PURSUANT TO RULE 24B-2 OF THE SECURITIES EXCHANGE ACT OF 1934, AS
AMENDED.

<PAGE>   4

Merger, the parties [*]. While the ultimate corporate structure of Aventis'
human pharmaceuticals business has not yet been determined, it is expected that
Aventis will consolidate the operations of RPR and the entities which formerly
comprised Hoechst Marion Roussel. In the event of such restructuring, the
Parties agree to negotiate further appropriate modifications to this Agreement
(whether by amendment of the definition of "Affiliate" as it relates to RPR or
otherwise) to reflect the intention described in this Section 11.2.

        7. All references in the Collaborative Research and License Agreement to
Rhone Poulenc S.A. are hereby amended to refer to Aventis S.A., and all
references in such agreement to Rhone-Poulenc Rorer Pharmaceuticals Inc. or RPR
are hereby amended to refer to Aventis Pharmaceuticals Products Inc. or APPI,
respectively.

        8. The address to which notices shall be delivered to APPI pursuant to
Section 11.4 of the Collaborative Research and License Agreement is hereby
changed to:

        Aventis Pharmaceuticals Products Inc.
        Route 202/206
        Bridgewater, New Jersey 08807
        Attention: General Counsel

        9. The amendments set out in this Amendment shall have effect as of
December 15, 1999, with the exception of Paragraph 8 which shall have effect as
of May 1, 2000. Except as expressly modified by this Amendment, all of the terms
and conditions of the Collaborative Research and License Agreement shall remain
in full force and effect.

[*] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY
BRACKETS, HAS BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE
COMMISSION PURSUANT TO RULE 24B-2 OF THE SECURITIES EXCHANGE ACT OF 1934, AS
AMENDED.

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        IN WITNESS WHEREOF, the Parties have caused this Amendment to be
executed by their respective duly authorised officers as of the day and year
first written above, each copy of which shall for all purposes be deemed to be
an original:

AXYS PHARMACEUTICALS, INC.                  AVENTIS

                                            PHARMACEUTICALS

                                            PRODUCTS INC.

By:                                         By:
   --------------------------------            ---------------------------------

Name:  Michael C. Venuti                    Name:  Ross J. Oehler

Title:  Sr. Vice President                  Title:  Assistant Secretary
        Research & Preclin Dev.
        Chief Technical Officer

[*] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY
BRACKETS, HAS BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE
COMMISSION PURSUANT TO RULE 24B-2 OF THE SECURITIES EXCHANGE ACT OF 1934, AS
AMENDED.

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                                   APPENDIX I

                                       [*]

[*] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY
BRACKETS, HAS BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE
COMMISSION PURSUANT TO RULE 24B-2 OF THE SECURITIES EXCHANGE ACT OF 1934, AS
AMENDED.

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