Questions:
Who called him as such?
What is the context?
Possibly an insult?
Alright, I'm checking it out again.
Clint is definitely introduced as a ring-tailed cat, but I found the two times where I saw Clint referred to as a "polecat" in Leo's route and it seems to be in Chase's neutral narrative description of him, not as an insult: when he shows up a Brian's trailer, and later when Chase and co. find him at Leo's place. 