The mutant named Catseye was one of the original members of the Hellions, the team of adolescent mutants formed by the Hellfire Club's then-White Queen, Emma Frost. Catseye was abandoned at birth, presumably due to her very visible feline mutation, and was raised by a cat who acted as her surrogate mother. In fact, Catseye originally thought herself to be a cat with the ability to take human form until she was found by Frost. Given the name Sharon Smith by Frost, the young mutant soon became emotionally attached to Frost, regarding her as a new surrogate mother.
Smith's youth and comparative lack of sophistication belie a ferocious intelligence. She was capable of total recall from her photographic memory, and instinctively knew when she was being lied to. Under Frost's tutelage, Smith progressed from total illiteracy to upper grade school reading levels in less than a year. She still retained several feline qualities whilst in human form, having been forced to provide for herself since earliest infancy.
Catseye was killed when her life-force was drained by the time-traveling Trevor Fitzroy following his assault on the Hellfire Club. Recently, Catseye was revived with an alien techno organic virus.