I have “not-really-but-kinda-OCs” like my OC/headcanon of Coral Witch as Meeshell’s BFF, otherwise I headcanon some backgrounders as “headcanon OCs” like :

❀ Isabella Beauty : True daughter of Beauty & the Beast (that beautiful background girl in a flowery blue and purple design with fur)

❄ Crystal Queen : True daughter of Snow Queen (that precious background girl with a royally frozen design)

⌚ Blanca Rabbit : True daughter of the White Rabbit (she appeared in the episode “Class Confusion”)

Of course all of them hate the real “not-them” characters. (and I hate them too)