Question: What role is the twin of Elaine Thompson most notable for playing in the television series "Casualty"?  

Context paragraphs:
Charlie Fairhead: Charlie Fairhead, played by Derek Thompson, is a fictional character from the BBC British medical drama "Casualty".  He is the longest-serving character having played the role of Charlie for over 30 years and the only remaining original character to have appeared continuously since the first episode on 6 September 1986.  Thompson chose to take a nine-month break from the show in early 2004.  Charlie left the show in series 18 on 17 July 2004 and after five months, returned on 1 January 2005 in series 19.  At the end of series 19, Charlie left again as Thompson returned to his break from the show, with Charlie's exit scenes airing on 20 August 2005.  After four months off-screen, Charlie returned in the series 20 Christmas crossover with "Holby City", which aired on 24 December 2005.  Thompson has remained with the show since, but regularly takes breaks of around two months every year.

Clive Mantle: Clive Andrew Mantle (born 3 June 1957) is an English actor.  He is best known for playing general surgeon Dr Mike Barratt in the BBC hospital drama series "Casualty" and "Holby City" in the 1990s, and is also noted for his role as Little John in the cult 1980s fantasy series "Robin of Sherwood".  He returned to "Casualty" in 2016 as Mike Barratt for the 30th anniversary.

Characters of Casualty: "Casualty" is a British medical drama television series that premiered on 6 September 1986 on BBC One.  The series was created by Jeremy Brock and Paul Unwin.  It is set in the fictional Holby City Hospital, in the equally fictitious city of Holby, and features occasional crossovers of characters and plots with spin-off show "Holby City".  "Casualty" follows the professional and personal lives of the doctors, nurses, paramedics, hospital management and patients at Holby General.  It features an ensemble cast of regular characters, and began with 10 main characters in its first series, all but two – Charlie Fairhead (played by Derek Thompson) and Lisa "Duffy" Duffin (played by Cathy Shipton) – have since left the show.  Many main characters have been written in and out of the series since.  In addition, "Casualty" features guest stars each week, as well as recurring guests that take part in story arcs that span a portion of a series or multiple series'.

Adie Allen: Adie Allen is a British actress who graduated from the Royal Academy of Dramatic Art, RADA in 1987.  She has appeared in new plays at the Royal Court, the Almeida, the Bush and the Tricycle Theatre(s).  She frequently appears on British television.  Notable television appearances include "Casualty" (she played student nurse Kelly Liddle in a number of episodes in 1991, the television series "99-1" playing Liz Hulley in 1994, Alan Ayckbourn's West End premiere of "Communicating Doors" at the Gielgud Theatre in 1996, playing the time-travelling prostitute Poopay, as well as the 1997 television drama "The Woman in White" playing Margaret Porcher, and the Peter Kosminsky film "The Innocents" playing Helen Rickard in 2000.  She was brought up in Bristol and was educated at Monks Park Comprehensive School, leaving when she was sixteen.

Odin's People: Odin's People was an Irish folk trio active in the 1960s, made up of twins Elaine and Derek Thompson and Larry Johns.  They released two singles on the Major Minor label in 1967.

Holby City (series 1): The first series of the British medical drama television series "Holby City" commenced airing in the United Kingdom on BBC One on 12 January 1999, and concluded on 9 March 1999.  The show was created by Mal Young and Tony McHale as a spin–off from the BBC medical drama "Casualty", intended to follow the treatment of patients from "Casualty" as they were transferred onto the hospital's surgical wards.  McHale served as the programme's lead writer throughout the first series, which ran for nine episodes.  Young cast actors who were already established names in the acting industry, particularly from a soap opera background.  Several cast members shadowed real surgeons and nurses in preparation for their roles to increase the show's realism.  The series received mixed reviews from critics.  It was compared favourably with "Casualty", but received negative reviews in which it was contrasted poorly with the American medical drama "ER".  The series première attracted 10.72 million viewers, falling to 8.51 million by the series finale.

Bobb'e J. Thompson: Bobb'e Jacques Thompson (born February 28, 1996) is an American actor, rapper and comedian.  He is known for: playing Tracy Jr. on "30 Rock"; his role as Stanley on "That's So Raven"; playing Ronnie Shields in "Role Models"; the role of Jimmy Mitchell on the short-lived NBC series "The Tracy Morgan Show", which lasted for one season from 2003–2004; his appearance in commercials for the PlayStation Portable; and for being the host of his own television series "Bobb'e Says", which aired on the Cartoon Network block CN Real, before choosing to opt out of a second season to do more films.  Thompson also had a recurring role on the hit series "Tyler Perry's House of Payne".  As a five year old, he performed Bow Wow's song "Bow Wow (That's My Name)", on a show hosted by Steve Harvey.  The video of this has been uploaded on YouTube and has over 3 million views.  He currently has a supporting role as M.J. Williams on "Tyler Perry's For Better or Worse".

List of Holby City episodes: "Holby City" is a British medical drama television series that premiered on 12 January 1999 on BBC One.  The series was created by Tony McHale and Mal Young as a spin-off from the established BBC medical drama "Casualty".  It is set in the same hospital as "Casualty", Holby General, in the fictional city of Holby, however "Holby City" is filmed at Elstree Studios in Borehamwood, while "Casualty" is filmed in Cardiff.  Occasional crossovers between the two shows are broadcast as "Casualty@Holby City".  In 2006, "HolbyBlue", a police procedural spin-off from "Holby City", went into production.  Its second season launched with a "Holby City" crossover episode.

Characters of Holby City: "Holby City" is a British medical drama television series that premiered on 12 January 1999 on BBC One.  The series was created by Tony McHale and Mal Young as a spin-off from the established BBC medical drama "Casualty".  It is set in the same hospital as "Casualty", Holby General, in the fictional city of Holby, and features occasional crossovers of characters and plots with both "Casualty" (in episodes broadcast as "Casualty@Holby City") and the show's 2007 police procedural spin-off "HolbyBlue".

Derek Thompson (actor): Derek Thompson (born 4 April 1948) is a Northern Irish actor, most notable for playing Charlie Fairhead in the long-running BBC television medical drama series "Casualty".  Thompson has played the role since the series' inception in 1986.

Supporting paragraphs: Odin's People Derek Thompson (actor)
Answer: Charlie Fairhead