Cave bear

The cave bear was a large, extinct bear which roamed Europe, including Britain and Austria, and northern Asia, including Russia and Mongolia, during the Ice Age.

Nimrod's Neanderthal tribe considered the cave bear holy and the tooth of one was a sign of great wisdom. Producing the tooth of a cave bear from a pocket on his chocolate brown blazer, the Seventh Doctor roused Nimrod from a state of unconsciousness. This also sparked Nimrod's recollection of the life he had led in his tribe, which Ace thought at first was a race memory before she found out he'd been preserved by Light. (TV: Ghost Light)