Why were rabbits with tentacles spotted in Fort Collins? Reason behind alarming growth explained

Fort Collins, Colorado residents have noticed wild rabbits with an abnormality that resembles tentacles protruding from the tops of their heads. The wild rabbits appear alarming and resemble the mythical creature, jackalope, that is until wildlife experts examined the rabbits and found there to be a scientific explanation.

According to Colorado Parks and Wildlife (CPW) the oddity is a skin virus, cottontail rabbit papillomavirus (CRPV), also referred to as shope papilloma virus (SPV).

The disease creates dark, horn-like masses or nodules mostly about the head, ears, and eyes of cottontail rabbits. Though the condition is unpleasant to look at, the virus poses no risk to humans and domesticated pets such as cats and dogs.

A bizarre virus is turning rabbits in the U.S. into grotesque, horned creatures with black, tentacle-like growths — and sightings are rising fast.



Known as the cottontail papilloma virus (CRPV) or Shope papilloma virus, it causes tumors to develop on or near the rabbits’ heads.… pic.twitter.com/jGs5nzqjDt

— Shadow of Ezra (@ShadowofEzra) August 12, 2025

According to a report by Coloradoan, Kara Van Hoose, a CPW spokesperson, stated that the growths almost never cause damage to wild rabbits unless they are blocking essential functions such as eating, drinking, or seeing.

Unfortunately, it is plausible the masses could grow large enough to hinder or block rabbits from seeing or eating, potentially leading to starvation. Rabbits usually have a healthy immune system that can resolve the infection on their own; however, the masses have the potential to become cancerous over time.

The disease is much worse in domestic rabbits, and pet owners are advised to contact a veterinarian for any signs of infection. Pet owners should also prevent their rabbits from interacting with wild rabbits.

A look into the history behind Jackalope and how the infection spreads amongst rabbits

People usually link the horned rabbit to the jackalope, a creature from American folklore that is said to be part jackrabbit and part antelope. Historians have traced the legend back to Wyoming in the 1930s, when a taxidermy mount of a rabbit with antlers helped to perpetuate the myth (High Country News).

It's important to know that while the actual growths caused by SPV resemble the mythical creature, they are not the result of a new animal species, but rather a viral infection.

The Jackalope is real. https://t.co/0uINMsAX6z pic.twitter.com/tYKcH5qeWb

— Billy 🚜 (@tractor_owner) August 12, 2025

SPV is transmitted primarily through insect bites, and particularly from ticks, fleas, and mosquitoes that tend to bite those less hairy areas like the ears and eyelids. Infection can also occur through direct contact between infected and healthy rabbits.

"The insects will target a rabbit on the ears, the eyelids, some of those areas that aren't as covered with the fur. That's where you'll see the growths, from the insect bite and then the virus itself," Beth Thompson, South Dakota's state veterinarian, told USA Today.

There have been several outbreaks over the years, but most outbreaks seem to occur in the late spring to summer months when insect activity is higher and rabbit populations are more condensed. Beth Thompson stated that it is very typical for those seasonal patterns to be consistent.

Wildlife officials advise residents not to approach, catch or feed infected rabbits. Although the virus does not harm humans, handling wild rabbits may put domestic rabbits at risk and inflict needless stress on the animal.