Cave bear
From Tardis Wiki, the free Doctor Who reference
The cave bear was a large, extinct bear which roamed Europe and northern Asia 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 his own jacket pocket, 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. (TV: Ghost Light)
