The animal I saw was much larger than this. I actually have seen minks; I posted about that here during the summer.

Dunno why the link doesn't work. I used it because it was a RI sub link. I'll see if I can find the original link to the post; it had a good discussion about local fishers.

Males are much larger than females. The one I saw was a male because it was at least 3.5 feet long, including the tail.

ETA: https://www.reddit.com/r/RhodeIsland/comments/oaegso/a_lovely_baby_fisher_cat_corralling_a_snake/