One of the most popular mutants to ever appear alongside the X-Men wasn’t actually a part of their original lineup. Nightcrawler made his debut in May 1975 in Giant Size X-Men #1 alongside Storm, Colossus and Thunderbird.

The events of Giant Size X-Men featured this new generation of X-Men joining forces with the original team’s leader, Cyclops, to rescue members of the team who had disappeared on a mission. After saving them from the sentient island of Krakoa, the new generation of X-Men continued to work with the old team.

Nightcrawler was created by Len Wein and Dave Cockrum – and was almost a DC character. Cockrum had created Nightcrawler and submitted him to be a part of DC’s “Outsiders” team in the Legion of Super-Heroes series, but was rejected. When Cockrum and Wein went to work on the new X-Men, the design was brought over to Marvel and thus, Nightcrawler became a mutant; he also became German in the move to Marvel because editor Roy Thomas had specifically asked for a multi-national team.

Nightcrawler stood out from other mutants insofar as he was slightly more colorful with his blue skin making him stand out in a crowd, for sure. His abilities include teleportation (always accompanied by the popular “bamf” sound effect), though he has also been able to blend seamlessly into the shadows, and his prehensile tail gives him an advantage in combat.

After spending several years with his fellow mutants on the X-Men, he left the team to join forces with Captain Britain in the UK alongside Shadowcat and Rachel Summers. The group they formed was called Excalibur, and while Captain Britain originally led them, Nightcrawler soon took over. After Excalibur disbanded, he returned to the X-Men. Since then, he’s featured prominently into storylines such as “House of M” and “Messiah Complex,” plus starred in his own book multiple times, the most recent one began in 2014.