Here's an interesting bit of comic-book history that puts quite a different perspective on Nightcrawler and his origins. Don't worry, Nightcrawler is still the same kind hearted teleporter that you've come to know and love since his debut in Marvel Comics Giant-Size X-Men #1 back in 1975. But before coming to Marvel, Nightcrawler was envisioned as a "rotten villain-type" character that hailed from an alien planet.
Dave Cockrum, who also co-created other classic X-Men like Storm and Colossus, initially created Nightcrawler back when he was the artist for DC Comics' Legion of Super-Heroes. But after a a dispute with DC, Cockrum headed to Marvel, along with Nightcrawler, who was just a drawing and a paragraph of information. The character design, along with the X conveniently already there on his uniform, and his teleporting abilities stayed in tact, but with the help of writers like Len Wein and Chris Claremont, his origins were given a complete overhaul to fit into the X-Men universe.
Taken from Cockrum's original background notes, here's the beloved Nightcrawler we know, compared to the Nightcrawler that would have ended up at DC:
Real Name: Kurt Wagner - Baalshazzar
Birthplace: Earth, mutant son of Mystique - Alien from a parallel dimension
Allegiance: Member of the X-Men - "Rotten villain-type" who merely "chooses to aid the law."
Sense of Humor: Always playing pranks on people, earning him the nickname "Trickster" - He would "think a truckload of dead babies was hilarious."
For more info, click the image below to enlarge, and head over to Marvel Executive Editor Tom Breevort's blog The Marvel Age of Comics.