Mazzranache is tameable by a Hunter. He is the most popular of the tallstrider family as a pet, due to his flamingo-like appearance. Up until patch 1.12, he had an unusually slow pursuit speed, which has since been normalized.
He is hostile, meaning if you get too close he will attack you, without you necessarily initiating the battle. He attacks with poison (a skill which is lost to him upon taming).
Mazzranache is mentioned in the quest  Mazzranache, although he is not part of the quest.