Lailoken is identified with Merlin in the late-15th-century "Lailoken and Kentigern", but the alternative name may already be present in the 12th-century dialogue of Myrddin with his twin sister Gwendydd (or Gwenddydd or Languoreth), for she addresses him several times as "Llallwg", for which the diminutive would be "Llallwgan".