Sabertooth tiger

The Sabretooth Tiger is a fossil that can be donated to the museum in Wild World and City Folk. A relative of modern felines, the sabretooh was named after its large front teeth that could shred through flesh with ease. Found in the Americas, the sabretooth went extinct on 10,000 years ago, during the last ice age.

Completing the Sabretooth in Wild World
New for Wild World, Blathers, the curator of the museum, will gladly talk about the sabretooth tiger after its fossil has been assembled:

"Hoo! Oh, hoo, how marvelous! I'm getting misty! The sabretooth tiger was an absolutely amazing beast! As its name implies, it was part of the cat family and had two long canine teeth. It could open its jaws incredibly wide, allowing it to tear into thick hides. It went extinct about 40,000 years ago...during a period when humans lived. I understand that humans also fell victim to this fierce hunter. The horror! Ah. Hoo. My apologies. I really should try to be more sensitive, eh wot?"

Completing the Sabretooth in City Folk
Again, Blathers will talk about the sabretooth's strength and demise when the fossil have been completed:

"...We're witness to glory! The sabre-toothed tiger is finished! Hootie WOOTIE! Such an event this is! As the name suggests, these fellows had two big, swordlike teeth, and they were a part of the cat family. They could open their jaws 180 degrees, allowing them to penetrate the thick hides of their prey! Savage! They went extinct 10,000 years ago... likely because there wasn't enough to eat! The mammoths they hunted were all eaten by humans instead, eh wot? HOO! I...beg your pardon! I was so enthralled, I... I spouted hot air like a boiling teapot, eh wot?"

The completed sabretooth tiger can be found next to the mammoth in the second fossil room, arranged in a running position, its jaw wide open.