Toon Town is a place where the High Council sends there members to film their stories to spread awareness of the friends. Doom was once a great toon actor playing many villain roles, similar to the collector, but an accident on the set made him think he was a real villain. Afterwards, doom was recruited by the friends to plant the seeds of distrust and bigotry against the toons in the human population of L.A., destroy toontown and try and try and find an entrance to looney tune land which he failed to do, meaning they're currently safe, though his weasels are capable of bringing him back with animation cels and a multiplance camera.
Dooms, shall we say, unique physiology may also make him an animated villain.
Dooms mission to open a hole into looney tune land may have failed, but that world eventually linked up with another band of animation canon in the non disney multiverse seperated, from the disney multiverse which one of chernabogs counterparts, a god of nightmares has embarked on a venture parallel to chernabogs