Slab

Slab was Mr. Sinister's recruit for his team Nasty Boys, and was one of the first of the team to attack their arch nemesis X-Factor. Slab climbed to the top of the Washington Monument and called Strong Guy out to fight him, and they battled. When he shrunk his size to avoid Strong Guy's punch leading to Strong Guy to destroy the monument.

Slab was captured along with his teammate Hairbag and taken to a holding cell by X-Factor. While he waited for his lawyer to negotiate bail, Slab and Hairbag were broken out of prison by the Mutant Liberation Front (of which Slab's sister Thumbelina was a member) and returned to the Nasty Boys shortly afterwards. 
 
Slab and the Nasty Boys reappear years later with Mr Sinister after Malice had possessed Havok in Hawaii. Mr. Sinister ordered his Nasty Boys to do whatever they pleased with Malice but to have Havok remain intact. Mr. Sinister appeared to have destroyed Malice when she attempted to possess Polaris. Slab and the rest of the Nasty Boys teleported away with Mr. Sinister after he had reassured Alex Summers that they would meet again one day. Slab has not been seen since the teams break -up but was shown to be one of the mutants to retain their powers after M-Day. 

Creation

Slab was created by Peter David and Larry Stroman in 1992 and first appeared in X-Factor # 74. 

Powers & Abilities

Slab has the ability to increase his size and mass. His increase in size and mass results in superhuman strength and durability.  
 

OTHER MEDIA 
X-MEN: The Animated Series 

 

Slab was in a few episodes of the series  Reunion, Part 1 & 2 (Episode 25 & 26)