In particular, right after Amos wounds the bear's shoulder. It roars in pain, then looks down at Amos with a Slasher Smile that the Joker would be proud of.
The confrontation between Tod and Copper at the den. You want to see what a realDeath Glare looks like? That kind of snarl is what an animal does when it intends to defend something to the death - and no less.