Critters 2 (1988)

A drunk in an Easter Bunny costume takes a leak and a critter jumps in the fly. One of the bounty hunters dies; another (maybe the same one) takes the form of a Playboy centerfold and walks around topless—with a huge staple in her belly, what? Later, a bunch of critters ball up into one big critter and roll around. [NOTE: This movie had a phone number you could call before it came out and listen to scenes from it. Did I call this number? Yes, I did.]

I remembered it vertical and lower down, but, yep, staple.