- You may be looking for buffalo.
Bison were Earth ruminants that K9 Mark I once encountered on a planet in another dimension, partially inhabited by ex-Tellac miners. They lived alongside other Earth animals from widely varying periods of evolutionary history. (PROSE: K9 and the Missing Planet)
Behind the scenes Edit
In the real world, bison and buffalo are often synonyms, especially when talking about the type of buffalo found in North America. However, the DWU fails to make this connection. Indeed, the implication in some texts, like Prelude Birthright, is that the Doctor and friends are encountering African buffalo which are not bison.