The Beast X men
Sticking with X-Men I want to talk about the "Beast" Dr. Henry Pillip which will agree he didn't have his story properly on the big screen, he is one of those less spoke of, I personally prefer the Beast from the X-Men cartoons.
His mutant ability gave him strength like an ape, but although he was gifted with all this he also has a superior intellect, which makes him a total package of having brains and strength.
Just to touch on he has some close similarities to the Hulk his powers came to him after been exposed to nuclear radiation, It's not the exact to Hulk but the storyline almost goes down that road. He has been one of the founding members of the X-men and a long-serving servant to the mutants