Sahara and Joker junior pictured here as babies are half hyena and half human.

Joker Jr (the one on the left) is different to his sister
in that he can actually turn into a hyena
once he gets a bit older and Sahara can't.

These actually are Jokers children but only in a AU (alternative universe) RP where Joker instead of being the cruel cunning prince of crime he was before has now mentally become a hyena along with his mate Lisa.