Fans of Spider-Man & His Amazing Friends must've wrongfully assumed that Firestar (Kathy Garver) was a unique mutant, but long time comics fans knew better.
In fact, the hero upon whom Firestar was based, Japan's Sunfire, made his TV debut in a season 1 episode bearing his name. Shiro Yashida, cousin of Wolverine's long-time honey, Mariko, was recruited by his uncle to in turn recruit Firestar to help power a nuclear reactor, unaware that his uncle actually intends far more sinister plans. Jerry Dexter was brought in to voice Sunfire, and I believe it is Keye Luke as his uncle.
Sunfire and Firestar fell in love, which must've disappointed anyone thinking that either Iceman or Spider-Man might have a chance with their red-headed teammate. Unfortunately, Sunfire would not return for a sequel.