Bauchan is one of the three ancient rat gods that make up what is known as the Raith Sidhe. He is a trickster who can take on any form he likes to walk unnoticed in the world. In art, he is depicted without a head as he can wear whichever one he desires.
In The Final Reckoning, Bauchan appeared as an old rat known as Barker. He acted as though he was barking mad, hence this alter ego's nickname. His mission was to learn the strength of Jupiter so the Raith Sidhe could determine how easy it would be for them to defeat him and return to power.