There Is No Such Animal
There is no recognized animal or creature called a "slough wolf." The term is likely made up, misheard, or misspelled.
Why It Is Not Real
"Slough" usually refers to a swampy or muddy area, not a type of animal.
"Wolf" refers to a specific canine species.
Possible Misinterpretations
"Slough" could be a misspelling of "slue" or "slew," terms related to twisting movements. The term might also be a fictional creation from a book, movie, or game.
How to Clarify
To get a better answer, provide more context: where did you hear the term, are you sure of the spelling, and what characteristics do you associate with it?