Prince Lir is the tritagonist of the story. He is the adopted son of King Haggard. He falls in love with Lady Amalthea and tries to earn her love in return, which is eventually successful and they become a couple. Although he later learns of her true identity as a unicorn, he isn't moved, as he loves her for who she is. He also tries to help her and her friends on their quest.
He is voiced by Jeff Bridges, whom is famous for Tron, Iron Man, and Surfs Up.