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

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

Colorado Parks and Wildlife: Scary-looking rabbits were hopping around Fort Collins. These weren’t your standard cute, fluffy bunnies; they had horn-like growths protruding from their faces and bodies.