Ibid was a snow owl. Supopsedly Ibid had all the knowledge in the universe and whoever had Ibid with them they could be given the answer to any question.
There is a belief that the flaw with Ibid is that the question he provides the answer to may not be the question you are seeking. For example if someone wanted to know about how best to defeat an enemy, Ibid may let you know who invented the Lyre.
The fact that Ibid is a Snow Owl is most likely why the Snow Owl is the sacred bird of Athena goddess of wisdom.