The Ancona Chicken item summons and dismisses an Ancona Chicken, a chickensmall pet that follows you around, meaning it is a non-combat pet and will not aid you in battle.
Patch 1.4.0 (2005-05-05): Ancona creature name changed to Ancona Chicken.
Cataclysm
This section concerns content exclusive to Cataclysm.
Magus Tirth goes mad after the Cataclysm and blames his apprentice, "Plucky" Johnson, constantly attacking him. After killing Tirth the player can talk to Johnson to buy some pet chickens.