When first introduced, the Beast — a mutant — possesses ape-like superhuman physical strength and agility and oversized hands and feet, though he otherwise appears to be a normal human being. Throughout his history, the Beast undergoes progressive transformations to his physiognomy, permanently gaining increasingly animalistic physical characteristics. These include blue fur, feline facial features, pointed ears, fangs, and claws. His physical power increases to even greater levels, as do his senses. Despite his savage appearance, he is a brilliant man of the arts and sciences; he is a world authority on biochemistry and genetics, the X-Men's medical doctor, and the science and mathematics instructor at the Xavier Institute (the X-Men's headquarters and school for young mutants). He is also a mutant political activist. Fighting his bestial instincts and fears of social rejection, the Beast dedicates his physical and mental gifts to the creation of a better world for man and mutant. He also has a witty sense of humor.