The Tasmanian Tiger (or Thylacine) was a fascinating animal that went extinct during the early 1930's. It was technically a carnivorous marsupial and looked like a strangely wonderful combination of a wolf, tiger, and kangaroo. Even at their peak population the tiger was rarely seen, and was most likely driven to extinction by dingos.
You can see a video of one of the last remaining tasmanian tigers alive in captivity. When I watch these clips I feel both sad and fascinated; it's like seeing a home movie of a dinosaur or dodo bird.