Perlo, Perna, Pernam
As Pernehan he is the younger brother of King Mark in the Prose Tristan. He was the smallest and ugliest son of King Felix. He condemned Mark for cowardice in surrendering a tribute to Ireland. In revenge for the insult, Mark slew Pernehan at the Fountain of the Lion while the two were hunting in the desert of Liantes.
There is a similar character in Malory named Bodwyne (Boudwin).