Grizzlies and Polar Bears will f*ck up every single other land animal with the exception of giraffes/elephants and potentially rhinos/hippos/juiced up ligers/sumatran tigers.
NA sure as hell packs the punch on that one.
It doesn't really have much land speed though.. that's the domain of the Africans.. besides peregrine falcon and red-tailed hawk and swift swallow. so it still comopetes in the air.
as for the bovines, I think musk oxen and bison could fukk up cape water buffalo. both are pretty underrated.
na's got it's citizen badass in the wolverine. which is outdone by Africa's Honey Badger easily. Also out done by Aussie's Tasmanian Devil.
it's canine is the best too. grey wolves > dingoes > hyenas (though hyenas have the strongest biting force.. females rape males (look it up)
The bird selection in NA is solid as hell with the eagles and owls and ospreys.. however there are condors and albatross that can match up. A lot of absolutely stunning birds of paradise are in Asia.
Snake-wise, NA is absolutely fukking garbage. Western diamondback is G.O.A.T
Aussie's got sea snakes off the coast in addition to the fierce snake (1 ml of venom kills 10,000 mice) taiapns. It's got marsupials too. Don't get started on Asia and SA, Afr..
Insect-wise, NA is again a joke. South American Red Bullet Ants will fukk a nikka up, Japanese hissin cockroaches and beatles will tear it apart. rhinocerous and dung beetles will reign hell on them.
nice Whales near NA tho. humpbacks and blues can be spotted.