Mushroom King
King Toadstool, the Mushroom King, is the king of the Mushroom Kingdom and Toadstool's father. He was mentioned in the Super Mario Bros. instruction manual but appeared mostly in the Mario comics. In the comics, he is depicted as a scatter-brained numbskull. King Toadstool most likely ruled the Mushroom Kingdom while Peach was a baby. However, it seems that the Princess herself became leader of the kingdom after she grew up.
Film
The Mushroom King, under the name King Bowser (not to be confused with the actual President Koopa), appears as a main character in the Super Mario Bros. film as Daisy's father. He had been de-evolved by President Koopa into a giant sentient fungus that had spread across the parallel world to obstruct Koopa's construction projects.
He continually aids Mario and Luigi throughout the film in their quest to defeat Koopa. Once they successfully do so, King Bowser reverts back to his human-form and exasperates "God, I love those plumbers!"
