Several fictional groups of mutants have used the name Hellions in American comic books published by Marvel Comics. The Hellions have always been portrayed as rivals of various teams of younger mutant heroes in the X-Men franchise, initially as actual villains and later on a team that was more of a school rival than actual enemies of the X-Men.

Emma Grace Frost is a character appearing in American comic books published by Marvel Comics. Created by writer Chris Claremont and artist/co-writer John Byrne, the character first appeared in The Uncanny X-Men #129. She belongs to a subspecies of humans called mutants who are born with superhuman abilities. Her mutation grants her high-level telepathic abilities and the power to turn into organic diamond. Emma Frost has evolved from a supervillain and foe of the X-Men to becoming a superhero and one of the team's most central members and leaders. The character has also been known as the White Queen and the Black King at various points in her history.