Toad

Sixty years of X-Men comics have produced exactly one henchman who outlasted every master he ever served. Mortimer Toynbee turned up in the original Brotherhood of Evil Mutants as Magneto's grovelling errand boy, a hunched mutant with monstrously overdeveloped legs who fetched, crouched and absorbed abuse in exchange for scraps of approval. Stan Lee and Jack Kirby built him as comic relief, and Chris Claremont later gave that cringing a cause: Magneto had spent years psychically breaking him. The reveal changed everything, because it meant the Toad was not naturally a worm.

Cut loose, he turned out to have ambition, competence and a grudge. He built and led his own Brotherhood, held his own against X-Men who had written him off, and slowly became the guy other villains underestimate exactly once. The Krakoa era completed the arc in the least likely way possible: a nation of his own, a relationship with Paige Guthrie, the X-Man called Husk, and a family life. Marvel's most disposable lackey ended up with the one thing his old boss kept promising and never delivered.

Toad is a Silver Age creation who survived by being useful to writers rather than to villains. Lee and Kirby needed a toady for Magneto's first Brotherhood; Claremont turned that into a study of an abuse victim; the 1990s let him lead his own Brotherhood; the early 2000s stuck him in Banshee's X-Corps; and the Krakoa era of 2019 to 2023 handed him citizenship, a partner and a child. He has never headlined a book, and that is precisely his value. Toad is the character Marvel uses to measure how much mutant society has actually changed, because he is always in the room and nobody ever expects anything of him.