Dragon

Dragon was one of Coach Zucchini's Evil Twin's helpers that was infamously known to green other Toons. Dragon was the de facto leader of the Team of Evil.

Dragon
The original Dragon was a short legged, fat red bunny with 105 laff. Dragon however, had very poor gags. Sometimes, Dragon was accompanied by one or more Team of Evil members to help him green other toons.

Dragon also helped The Evil Twin create videos on how to train gags such as Lure and Trap, and also helped The Evil Twin show people how to green in a VP boss battle.

Dragon Reborn
Dragon Reborn was The Evil Twin's second iteration of Dragon who also sported poor gags. Despite this, Dragon Reborn was still a force to be reckoned with as he was often accompanied with at least one or more Team of Evil members. The only difference was that Dragon Reborn was blue instead of red.

Dragon Reborn was the main protagonist for Lets Green Toontown which lasted for 12 episodes.

Sometime after episode 12, Dragon was imprisoned because of his serial greening of other Toons.

Unicorn
Unicorn was the third iteration of Dragon. Unicorn was the protagonist of the series Let's Green Toontown Rewritten. Unicorn was actually Dragon in disguise because he went to The Blizzard Wizard to turn him into Unicorn to evade Joey and the moderation team after sneaking out of Toontown prison.

The identity of Unicorn was chosen because it can be considered to be the opposite of a dragon.

Much like his past self, Unicorn had poor gags so he was usually accompanied by members of The Team of Evil. Unicorn was frequently accompanied by Team of Evil members Gengar the purple pig and Ryan the yellow duck.

Gekko
Before Episode 9 of Let's Green Toontown Rewritten, Unicorn changed his DNA (with the help of The Blizzard Wizard) to a green dog and was also able to trick the moderation team into changing his name to Gekko.

Unfortunately after Episode 9 of Let's Green Toontown Rewritten, Joey and his moderation team realized that Gekko was actually Dragon. The moderation team swiftly banned Gekko and threw him back into Toontown prison for his crimes against the Toons.

Dragon Rewritten
Dragon Rewritten was a fanmade recreation of the original Dragon.