As I remember it, no one has ever seen a shagamaw (at least and lived to talk about it). This led some to speculate that it could be a BF. The only way you knew they existed was the fact that things would go missing along the tote road, and sometimes the weird tracks. Here is a few articles I found after a copernic search on the internet:
shagamaw n : mythical Maine creature Bipedester deleuissimus with two bear forefeet, and two moose hindfeet, which it varies alternately, making it tricky to track.
The Tote-Road Shagamaw: Uncatalogued Creature Lore From the Rangeley Lakes to Allegash, on into New Brunswick, loggers tell of an animal that has baffled many-a-man, even those who ain't strangers in the New England Woods. It starts as such: report of bear tracks seen near camp is circulated; soon thereafter, initial reports are denied and moose tracks are reported instead; heated argument breaks out between two men, one saying, "You don't think I know the diff'ernce 'tween bear and moose track you idjit!"; fist fight occurs.
To only a few timber cruisers and rivermen is the explanation of these mysterious changing tracks known.
Gus Demo, of Oldtown, Maine, hunted and trapped in the Maine woods for nearly a half-century. He once come upon what he clearly recognized as moose track and scat.
Mr. Demo: "I follered the tracks for 80 rods, when to my utter astonishment, they suddenly changed to bear track and scat. I go, 'Huh?' No lie. Then, I took up followin' them tracks another 80 rods when they switched back over to moose track and more scat. I go, 'What the?' Amid my surprise, I did take the notion to mark it off, and I calculated that these switchovers happened once every quarter mile, to the foot, and that the steps was exactly one yard apart. Furthermore, I noted, mentally a course, that these mysterious tracks always foll'erd a tote-road or blazed line through the woods.
"This once, I come into sight of the creature, 'twas bizarre, sir, indeed 'twas. I saw it had hind feet like that of bear and fore feet like that of moose. 'Twas the most curious animal I'd seen since or since then. I noted, mentally you see, being without pencil and pad - as so often we find ourselfs in the woods - that the animal paced itself very slowly, as though it were counting its steps. It was walking up on its hind feet, something like a human, though clumsier, then swung and pivoted and walked on its front feet and resumed its heedful pacing."
Mr. Demo reasoned that the animal, the "shagamaw" as he named it later, walked this way because it was an imitative animal and it wanted to be like humans. The creature had observed surveyors carefully moving though the woods or trappers patiently stalking some fur-bearing animal. He speculated, also, that the animal did, in fact, count its steps and could only count as high as 440 (the number of yards in one quarter mile), therefore, it had to pivot and switch from front-to-back or vice versa, in order to keep track of its tracks.
With regard to the strange biology of the animal, Mr. Demo has theorized less extensively, saying, "I'm a woodsman, not a scientist." He did once mention that perhaps the weird animal was "the result of a hex cast forth by some damn wizard."

The Argopelter
Also called a forest monkey, this cute little squirrel-like animal was so friendly, it was nearly hunted to extinction. Then the lumbermen taught argopelters to protect themselves by throwing bits of wood at anyone who would come near their tree-holes. They became chunk chuckers. If you’re walking in the woods and get hit by a falling branch, it was probably thrown by an argopelter.
The Squonk
Pity this poor creature. Its loose, wrinkly skin is covered with bumps and moles. The squonk feels so sorry for itself it just sits and moans. When faced with danger, this little animal quickly dissolves itself with its tears. If you want to catch one, try it in winter. They move around less and their tears fall slower.

The Billdad
Imagine a small kangaroo with a flat tail, webbed feet and a bill like a hawk. That’s the bildad. Since it’s such a good jumper, it waits by the shore of a pond for a fish to rise. Then it leaps over the fish and smacks it with its flat tail. Jumping half the length of a football field is nothing to the bildad.
The Shagamaw
This animal confused woodsmen for a long time, because its front legs are those of a bear, but its back legs are just like a moose’s. It walks 440 steps with its front legs, then quickly hops to its back legs, leaving very confusing trails. The shagamaw’s favorite snack is a lumberjack’s drying shirt on a laundry line.