Cyclops: Scott Summers was the first mutant recruited to the X-Men by Charles Xavier. With powerful optic blasts capable of immense destruction, Scott took the name Cyclops and controlled his power with a special ruby quartz visor.
Beast: Hank McCoy's mutant agility and enhanced physical attributes helped him achieve athletic superiority in high school before causing a rift with "normal" students and leading McCoy to join the X-Men.
Marvel Girl: Brought to Charles Xavier for treatment after psychically sharing the death of her best friend Annie Richards, Jean Grey's telepathy and telekinesis were blocked until she could better control her mutant powers and join the X-Men.
Iceman: After accidentally using his mutant control over ice to show a local bully the error of his ways, young Bobby Drake is recruited by Professor Xavier and Cyclops to be the second member of the founding X-Men.