Prince Lir is a renowned hero and the tritagonist of the 1968 novel, The Last Unicorn by Peter S. Beagle and the 1982 Rankin/Bass film adaptation of the same name.
He is the adoptive son of King Haggard and the prince of a dreary town known as Hagsgate who serves as the last unicorn Amalthea's love interest. In the novel, but not revealed in the film, Lir is actually the descendant of a unicorn-turned-man. Schmendrick's master turned Lir's ancestor into a human and he fell in love with a mortal woman, giving up his immortality to be with her.
He is voiced by Jeff Bridges, whom is famous for Tron, Iron Man, and Surfs Up.