Dark Vegan is an antagonist who first appeared in "Johnny Test in Outer Space".
Dark Vegan is the leader of Vegandon, a fertile utopian planet inhabited by a species called Vegans. He first appeared in "Johnny in Outer Space", in which it is revealed that his method of sustaining the utopia that is Vegandon is to suck the resources of other planets and use them on Vegandon. In "Johnny X: The Final Ending (JX6-b)" he comes back to get revenge on Johnny, but with the help of Johnny and the Johnny Helping Not So Evil Force 5 and Vegan's daughter Jillian, Dukey, Susan, Mary, and the military, Dark Vegan was defeated once again, after which he started living on Earth. He starts to change his mind about Earth after Johnny introduces him to toast, which soon becomes his new favorite food. He had a cameo appearance in "Join The Johnny Scouts" when Johnny wanted to - and succeeds in - selling him Ladybird Scout cookies. Dark Vegan also appeared in "Dark Johnny". He later returned to Vegandon but left the planet and returned to Earth the moment he learned that Vegandon doesn't have toast. He is a parody of Darth Vader from the Star Wars franchise, but his appearance and behavior is similar to Dark Helmet of the movie Spaceballs (who is also a Darth Vader parody).
- Dark Vegan is a parody of Darth Vader from the Star Wars series.
- Susan and Mary do not seem to fear him in Dark Johnny.
- In "Johnny vs. The Tickler" he had 2 different helmets before the one he always wears
- He loves toast to a point of obsession, and will do almost anything to get more.
- He's very sensitive towards his vegtable garden.
- In "It's Easter, Johnny Test!", he is revealed to be allergic to gamma radiation with the main effect being breaking out in hives.
- Just like Dark Laser (another Darth Vader parody) trying to get revenge on Timmy Turner in The Fairly OddParents, he's spends the entire series trying to get revenge on Johnny.