Ludo is a major antagonist of Star vs. the Forces of Evil. In season 1, he uses an army of monsters in order to steal Star's wand and take over the universe. Throughout season 2, however, he has his own wand and new monster followers. Toward the end of season 2, his body is possessed by Toffee.
At the beginning of season 3, Ludo discovers that his wand has become his right hand. Using this, he briefly takes over the Butterfly Kingdom, but ultimately decides to go on a soul-searching journey after Toffee's final defeat.