Viral photos have inspired a fluffle of unflattering nicknames, including "Frankenstein bunnies," "demon rabbits" and "zombie rabbits."

The unsightly bunnies are infected with cottontail rabbit papillomavirus, which can cause growths that resemble warts or tentacles.

Some cottontail rabbits in Fort Collins, Colorado, have been drawing attention because they have wart-like growths on their faces that look like horns.