Michael McKean's Chewed Up Arm In Today's Daily TwitPic

I'll warn you now, today's Daily TwitPic is hard to look at. It's obviously not real, but special effects folks are doing incredible things with latex and makeup these days.
What I can't figure out is where this photo comes from. I initially saw it and thought, "Huh, I didn't know Michael McKean had a 'Piranha [...]

Georgina Grenville Gina Carano Gina Gershon Gina Philips Gisele Bündchen Giuliana DePandi Giulianna Ramirez