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.

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

Northern Colorado—specifically a town called Fort Collins—has recently made headlines for its rabbit population after it was revealed that several of them had long black tentacles growing all over their bodies.