His name is also spelled Anir and he could me well be known as Amhar in the Mabinogion. http://www.earlybritishkingdoms.com/bios/amir.html says he may be Smerbe in the genealogy of the Campbell clan. http://www.btinternet.com/~yeatesprint/ross/arthur.html says Licat Amr is Wormelow Tump near Much Dewchurch, referring to it as the burial place of Mordred. So he may be appearing as Mordred in later texts.