Prince Merkimer is the son and nephew of King Lorenzo I and Queen Bunny. He was designated to marry Princess Bean when she impaled Prince Guysbert, his brother, who was up until that point the groom-to-be.
Prince Merkimer is an arrogant nobleman with a large ego, he believed that before he was to marry Bean, she would have had an affair with him anyhow, because he believes he is irresistible and obviously superior.
He once learned that a dragon could shoot fire out of both ends. He was eventually turned into a pig after drinking a magic potion that consisted of elf and pig blood. He is now pathetic and lonely. So much so, he loses his dignity over the mere mention of cabbage.