King Leonidas is the ruler of the isle of Naboombu. He is boisterous, brash, but a party animal if he is calm and doesn't let his temper get the best of him. He is a humanoid lion wearing a yellow shirt and shorts, a king's robe and crown and a red sash with the Star of Astorath. He is voiced by Lennie Wenrib.
King Leonidas is first seen taking his anger out on the Secratary Bird until Mr. Browne shows up and volunteers to be a referee at the soccor game he wanted to do. He plays soccor like a pro, but will not cease unless he wins. When one of his teammates, the rhino pops the ball, he roars so loud that both teams enter the goal and he blows it making it go onto the other side. The Star of Astorath was stolen by Mr. Browne who switches it with the referee whistle. He says goodbye to the humans, but finds out from the Secretary Bird and goes after the humans in an angered rage. He is transformed into a rabbit by Miss Price and since rabbit spells are temporarily, he presumily transforms back into his regular lion form.
In "Magic Mysery", he remembers his experience with Miss Price and Mr. Browne, but he becomes more trusting towards humans despite what happened to the Star incident. He also kind of forms a bond with Tracy and Jessy and makes them play on his soccor team.
- He looks simular to Prince John from "Robin Hood" in simularities.
- He speaks like a pirate sort of.
- MCF and the Magic Mystery(debut)