Tree-Squeak. - [Fearsome Critter]
• About this critter: An unknown creature said to be heard far more often than seen - yet often described as "Weasel, Bird or Squirrel-like." it was used to explain misplaced, unexplainable sounds or noises from an unknown source in the woods. [as the creatures name suggests, most often its blamed for the sound of trees squeaking, rubbing together in a forest, these noises sound somewhat like an animal call & blamed on this critter] However, The creature is said to have a variety of calls: "a whine like a panther, a squeal like a young pig, and sometimes a roar like machinery or a bunch of fire crackers going off." - The animals fur is also said to be able to match tree bark exactly allowing it to hide in plain sight, camouflaging itself like a chameleon.
• History: The Tree Squeak was probably earliest defined as "an imaginary bird or animal. Really the noise made by trees rubbing in the wind, resembling the cry of a bird or wild animal." This definition is from Dialect Notes. [1890.] - These along with a long list of other slang phrases where provided by one Mr. Bartle T. Harvey: Assistant Entomologist of the U.S.Gov. Forest Service from Maine – according to him; the slang was also used within the lumber industry in the Lake states, Oregon and Washington. - Meaning that the 'tree squeak' and other critters like it, where in fact being spread orally long before they where first properly illustrated or catalogued.
[Note that the "Swamp Gaboon" and "Wampus Cat" are also listed and used to describe similar unknowable creatures, unknown animal cry's or where blamed for leaving strange tracks.]
Fast forward a bit to 1939, Henry H Tryon decided to include the supposed creature in his fearsome critters book where he described it as follows:
"Some folks will claim that the mating call of the Treesqueak is just a dry tree lodged in a “school marm.“ But we old boys know better. The sound is made by an untrustworthy animal still quite common in the North Woods. Built something like a weasel, and with the same nice, friendly disposition. He is chameleon-like, and can wrap himself around a tree-trunk and match the bark exactly.
He is sometimes aggressive, but only after a long, dry spell. Has a variety of calls; a whine like a panther, a squeal like a young pig, and sometimes a roar like a bunch of cannon crackers at a shotgun wedding. Look out for him on windy days along towards sundown. "
[The tree squeak as illustrated by Margaret R. Tryon.]
• Variants & Similar Critters: According to one CBC Radio Interview [catalogued & transcribed by Alexander, Maine museum.] "Jack Dudley" a retired attorney who lived off shore on Pokomoonshine Lake. had been cataloguing creatures like the tree squeak as a hobby for more than 25 years. – He describes the creature (which he apparently had mounted) as "Small, 6" - 9" limbless-flying-squirrel-like mammals without any limbs, suction cups all over their bellies." - [Sounds a bit like a large caterpillar to me.] - Apparently this variation of the treesqueak can only get around on particularly windy days when the trees bump into each other or on humid nights when they can "travel on moonbeams" - if they fell to the ground, they'd be unable to get back up & they'd freeze or starve to death, the creatures range was quite limited for that reason.
Because of the purpose of being an unknown creature used to describe strange noises on windy nights", One might also consider Art S Childs: Accordianteater, as well as the Treehopper [yarns of the big woods, 1922-25] -As Tree Squeak variants as well, regardless if they're properly related or not, I'd classify these creatures as a type of Audio phenomena.
• Pop Culture: According to Roal Dahls: "Charlie and the great glass elevator" (the 1972 sequel to charlie and the chocolate factory) Treesqueak eggs are one of the ingredients listed in wonka-ite.
a "Tree Squeak" also appears as an elves familiar in the Shannara series of books.