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

As weird and concerning as they appear, the virus that causes the dark, wart-like horns or tentacles to grow on cottontail rabbits is relatively common and usually not anything to worry about.

A disturbing virus is sweeping through bunnies in Colorado in the US, turning them into nightmarish ''Frankenstein'-looking mammals with scary tentacles protruding out of their faces. Read on to know more about the shope papilloma virus.