Weasel

Megalictis (Creature 3), Weasel (Creature -1)

Weasels have a particularly strong musk that they use to mark their territories. This primarily discourages other weasels from competing for prey, but it can also be used to discourage predators. It's certainly effective against trappers and fur traders, who find the smell nearly impossible to remove from the pelts, and thus trappers favor the closely related stoat (also known as an ermine), which has similarly soft fur but less pungent defenses.