What is "avitohol"

Avitohol (153?–453?) is the first name in the Nominalia of the Bulgarian khans. Little is known about him. According to the document he is from the Dulo clan and most probably was considered and respected as the forefather of the khans. Some researchers claim that Avitohol is Attila the Hun who was succeeded by his son Ernak or Irnik (the second name mentioned in the Nominalia). Others suggests that Avitohol was a semi-legendary ruler who may have been either a descendent or an ancestor of Attila (see Dulo clan).