River Butterfly

King River and Queen Moon are the parents of Star Butterfly, and the rulers of the extra dimensional kingdom of Mewni, from the show Star vs. the Forces of Evil.

King Butterfly
Despite seeming just as formal and strict as his wife, it is revealed in "Diaz Family Vacation" that he enjoys fighting monsters like Star does, whenever his duties as king bore him.

Queen Butterfly
She was once the previous owner of the Magic Wand before passing it onto her daughter on her fourteenth birthday. She is known to be serious most of the time, having low tolerance for anything messy or destructive, which is why she disapproves of Star's reckless and irresponsible behaviour.

Trivia

 * In "Storm the Castle" it is revealed that King Butterfly's first name is River.
 * According to Daron Nefcy, Queen Butterfly's first name is Moon.
 * In Season Two, Queen Moon receives a redesign to her appearance.
 * In "Into the Wand", it is revealed that Queen Butterfly was the one who first defeated Toffee and severed the middle finger on his right hand.