Since all Anti-Fairies are complete and utter opposites to their fairies counterparts, Anti-Cosmo is the total alternative to everything that makes up the original Cosmo.
While the normal Cosmo is amazingly dumb yet kind and caring, Anti-Cosmo is the opposite as he is an evil criminal mastermind and is very ruthless in his ambition to become more powerful so that he can cause even more bad luck among humans, an ambition shared by all his Anti-Fairies cohorts, of whom he is apparently the ringleader of.
After he is permanently freed from Jorgen Von Strangle's captivity, he and his race move to Anti-Fairy World where he rules over them from Anti-Cosmo's Castle where to this day, they are still a threat to the fairies.
Anti-Cosmo has a blue and black color scheme consisting of a blue bowler hat in place of a crown, fangs, and bat wings like those of all Anti-Fairies. He wears a monocle over his right eye which he cannot see without, and wears a kind of coat or suit and, unlike Cosmo, Anti-Cosmo speaks intelligently with a stereotypical British accent.
Being Cosmo's complete opposite, Anti-Cosmo is far more intelligent, evil, and devious than most other villains on the show, let alone his counterpart Cosmo.
Unlike the normal Cosmo who is dimwitted and always being told what to do by other fairies, Anti-Cosmo is a diabolical criminal mastermind and he is also the leader of the Anti-Fairies.
Anti-Cosmo has a British accent, while Cosmo does a terrible British impersonation.
Anti-Cosmo didn't give birth to Foop, who was instead born from Anti-Wanda.
Cosmo loves red meat (ex. Bacon and Weiners), so, Anti-Cosmo probably hates red meat.