The growths are most likely caused by a summertime virus common in some U.S. states, but wildlife officials say there is no risk of transmission to humans or other animals.

A parade of so-called “zombie” rabbits sporting hornlike growths has sparked confusion and concern in Colorado. Wildlife officials say there’s no cause for alarm. These unusual creatures are simply living with a harmless,

They may look like real-life jackalopes, but these rabbits owe their peculiar appearance to an infection caused by a cousin of the human papillomavirus.