|Appeared in||X-Men: The Last Stand|
Leech plays a pivotal role as the source of the "cure" for the mutant X-Gene, the cure being a sort of retroviral gene therapy using Leech's DNA. His power automatically cancels the mutation of any mutant within a few feet of him, including reversing physical mutations such as Hank McCoy's blue fur. When McCoy reaches out to shake Jimmy's hand, his own hand loses its furry blue appearance; the mutation returns once he leaves Leech's presence. Magneto plans to kill Leech, who is being kept at Alcatraz, thus destroying the mutant cure (at that point they had no way of synthesizing the cure artificially) and preserving the mutant species. Magneto and his Brotherhood of Mutants attack the facility, which is defended by federal troops and the X-Men. During the battle, Juggernaut is sent to find Jimmy and Kitty Pryde races to save him. Juggernaut is defeated when Kitty uses Leech's nullification power against him, taunting him into charging at them head-on so he'll knock himself out against the wall. Kitty and Jimmy then escape the building through the holes that Juggernaut smashed on his way in. Later, Jimmy is seen evacuating Alcatraz Island with Pryde and Bobby Drake. Jimmy is then seen as a member of the Xavier Institute and is received by the new leader, Storm.
- Mutation Negation: Jimmy can negate other mutant powers and mutation if they are near from him. For example, Juggernaut strength and resistance no Also, with his blood, the government was able to create a serum that temporarily cure mutants.
- Warren Worthington II - Test doctor.
- Kavita Rao - Attending physician and researcher.
- Kitty Pryde - Savior.
- Juggernaut - Enemy.
- Storm - Teacher.
- Brotherhood of Mutants - Enemies.
Behind the scenes
To be added
- In the comics, Leech has a frog like appearance with green skin and lives in the sewers with mutants called The Morlocks.
- Leech's role in the mutant cure in the film replaces the role of the alien ambassador Ord who introduced the cure in the comics.