10. American bison (Bison bison) - The American bison is the largest land mammal in North America.
9. Moose (Alces alces) - The moose is the largest member of the deer family.
8. Grizzly bear (Ursus arctos horribilis) - The grizzly bear is a subspecies of the brown bear that is found in North America.
7. Walrus (Odobenus rosmarus) - The walrus is a large marine mammal that is found in the Arctic Ocean.
6. Beluga whale (Delphinapterus leucas) - The beluga whale is a white whale that is found in the Arctic Ocean.
5. Humpback whale (Megaptera novaeangliae) - The humpback whale is a large whale that is found in all the oceans.
4. American alligator (Alligator mississippiensis) - The American alligator is the largest reptile in North America.
3. Polar bear (Ursus maritimus) - The polar bear is the largest land predator in the world.
2. Killer whale (Orcinus orca) - The killer whale is the largest species of dolphin.
1. Gray whale (Eschrichtius robustus) - The gray whale is a large whale that is found in the North Pacific Ocean.