A partially-chewed stick
This is, as the description implies, a stick that appears it has been gnawed on fairly throughily. The teeth marks are mostly confined to one end, but only mostly.
Byron has demonstrated that he can chew on the stick to make seemingly random things happen, and The Fuzoku Butsu have expressed an interest in acquiring the stick as well as (perhaps) a respect bordering on fear for it.
According to a rather cranky aspect of Aisling, it is “unbound by fate”. What exactly that means is a little unclear, but it seems to be able to move through the tapestry of possibilities without prediction.