Bezoar:
A bezoar is a mass found trapped in the gastrointestinal system, though it can occur in other locations. A pseudobezoar is an indigestible object introduced intentionally into the digestive system.
There are several varieties of bezoar, some of which have inorganic constituents and others organic. The term has both a modern (medical, scientific) and a traditional usage. [Wikipedia]
Noted at the new Bell Museum yesterday. They just described it as a cow hairball.
