The X-Men fight against not just super-villains, but also spiritual evils like bigotry. The mutant most liable to suffer hate and fear is the blue-skinned Bavarian Kurt Wagner/Nightcrawler, who doesn't pass for human the way most of his comrades do.
Nightcrawler's first appearance in Len Wein and Dave Cockrum's 1975 "Giant-Size X-Men" #1 saw Professor X rescue him from a pitchfork-and-torches mob. Yet, Nightcrawler is the kindest X-Man of all. As Kurt's teammate Kitty Pryde has attested, Nightcrawler had "every excuse to become as much of a demon inside and out, but he decided he'd rather learn to laugh instead!"
Though excluded from the main cast of the 1992 "X-Men" cartoon (until revival "X-Men '97"), Nightcrawler made a memorable guest appearance in an eponymous episode. "Nightcrawler" directly centered on the defining irony of Nightcrawler: his Catholicism. He's a man of God even though he looks like he was made in Satan's image. His teleportation power even leaves behind smoke that smells of hellish brimstone!