Once Upon a Giant (1988)

Lester and Humphrey are the Royal Jester and Doctor, respectively, in a Kingdom terrorized by a mysterious giant whose presence is known only by his horrible voice and giant shadow. The giant takes the crown jewels which permit the Evil Prince Malokeo to convince the King to let him marry Princess Marigold. Marigold, horrified at the prospect and in love with Prince Daryl, turns to her friends Lester and Humphrey for help.