A mustelid like wolverines, otters, and weasels that lives in high altitude pine forests. The American Marten is known to be curious and not particularly scared of humans, this is why many pictures have them staring at the cameraman.
Cute murder floof.
The whole family of mustalids are fantastic at hunting when they elect to do so. Fishers routinely feed on porcupines and a wolverine (which weigh ~30lb vs the marten's 3lbs) once killed a polar bear, both were captive animals in a zoo. Also if you look it up there are videos of 7 oz weasels taking down rabbits much larger than them.
We're lucky there aren't any 90lb mustalids.