Warning Issued As ‘Frankenstein Rabbits’ With Tentacle Growths Spread Across The US

Fort Collins, Colorado – The rolling plains and suburban sprawl of Fort Collins have recently become home to an unsettling spectacle: clusters of common rabbits bearing grotesque, black, tentacle-like growths sprouting from their heads and faces. Local residents, stunned by the creatures’ increasingly monstrous appearance, have taken to calling them “Frankenstein rabbits.” Wildlife officials are now sounding the alarm, urging Coloradans—and, increasingly, people across the Midwest—to avoid contact with the infected animals.

From Fable to Frights: The Reality Behind the Myth

The viral images flooding social media might seem like hoaxes or the stuff of tall tales—yet these “horned” rabbits are all too real. Since early 2024, sightings have multiplied. It was then that an anonymous local uploaded a chilling photo online: a rabbit’s skull almost entirely shrouded by an array of black, spike-like protrusions.

“I’d never seen anything like it,” recalls Susan Mansfield, a Fort Collins resident who spotted one of the animals prowling her backyard late last spring. “It looked like black quills or toothpicks sticking out from all around its mouth. I thought he’d die off during the winter, but he didn’t. He came back the next year—and the growths were bigger.”

The Culprit: Cottontail Papilloma Virus

Experts reveal that the bizarre transformation is linked to infection by the cottontail papilloma virus (CRPV), sometimes still called the Shope papilloma virus after the scientist who first described it in the 1930s. This DNA virus targets wild rabbits, most notably the eastern cottontail, but sightings are rising among other common species as well.

Infected rabbits initially develop small red, raised patches—usually around the eyelids, mouth, ears, and sometimes even the nose. Those patches soon morph into hard, wart-like tumors that can, in severe cases, grow into elongated, keratinized “horns” and even tentacle-like projections. In creepiest cases, these protrusions give rise to the mythic creatures of American folklore: jackalopes, or rabbits with antelope horns, long beloved in roadside legends but now hauntingly visible in suburban lawns.

A Virus on the Move

Animal health authorities warn that CRPV is not confined to Colorado. “Cottontail papilloma virus has always existed in wild rabbit populations, particularly in the Midwest,” says Dr. Valerie Noon, a wildlife pathologist at Colorado State University. “But this year, we’ve seen a notable spike in reports and severity of symptoms—likely due to changes in mosquito and tick populations driven by wet weather.”

CRPV is primarily spread through bites from blood-feeding insects, especially mosquitoes and ticks. When an infected insect feeds on a healthy rabbit and then bites another, viral transmission occurs—leading to fresh outbreaks. Direct contact between rabbits can also play a secondary role, especially when wounds are present, but the overwhelming majority of infections begin with insects.

Researchers confirm that, so far, there are no documented cases of CRPV transferring directly to humans or pets, either by bites or by handling. Nevertheless, Colorado Parks and Wildlife (CPW) and veterinary experts urge the public not to approach or attempt to rescue “horned” rabbits. Infected animals are often immunocompromised and may become aggressive if approached.

The Path from Unsightly Warts to Deadly Disease

While the sight of a rabbit bristling with tentacles is alarming, the medical process behind the transformation is even more disturbing. Red, inflamed papillomas develop first, quickly hardening into growths made from keratin—the tough protein that also makes up our hair and nails.

For the afflicted rabbit, these tumors are more than cosmetic. “The growths sometimes obscure the animal’s vision or block its nostrils, making it hard to eat, navigate, or even breathe,” Dr. Noon explains. In severe outbreaks, tumors may grow so large that they obstruct the mouth, leading to slow starvation.

Most tragically, some papillomas mutate further into squamous cell carcinoma, a dangerous and potentially fatal cancer. In the wild, untreated rabbits suffering from malignant tumors rarely survive more than a season.

Concerned Pet Parents

Worries among pet rabbit owners are also mounting. Although house rabbits are far less likely to contract CRPV than their wild cousins, the possibility of infection remains—especially if an indoor rabbit is allowed outdoors, even briefly.

Veterinary professionals urge owners to keep pet rabbits indoors and protected from mosquitoes and ticks. If warty growths are noticed, immediate veterinary attention is needed. “The good news is that surgery can remove the tumors if caught early, before malignancy sets in,” says Dr. Janet Kim, a Denver-area exotics vet. “But prevention—mostly by insect control—is by far the best approach.”

What To Do If You Encounter an Infected Rabbit

Colorado Parks and Wildlife has been explicit: do not touch or try to care for rabbits with abnormal growths. These are wild animals, often severely stressed and immunocompromised. Handling them can cause additional suffering—and in rare cases, could expose other animals to the virus if proper hygiene isn’t observed.

If you find a diseased rabbit, local wildlife officials recommend:

Leave the animal alone and keep pets, especially other rabbits, at a distance.
Report the sighting to local wildlife authorities if the animal is in a public space or poses a risk to others.
Do not attempt to euthanize or remove the animal yourself.

Moral Dilemmas and Online Reactions

As photos and videos continue to spread across Reddit, Facebook, and wildlife forums, the public has debated the ethics of “helping” infected rabbits. “Is it more humane to euthanize them or is it better to let nature take its course?” wonders one user. Animal control agencies thus far have offered no guidance, indicating that the virus is not considered a public health concern.

The Jackalope: Science Behind the Legend

The notion of a “horned rabbit” is far from new. In fact, the legendary jackalope—a rabbit with antelope-style horns—finds its roots in historical instances of CRPV infection. Naturalists as far back as 1789, in works like the famed Tableau encyclopédique et méthodique, documented rabbits with strange head growths, likely severely afflicted by what we now know is CRPV.

While the legend has long been fodder for pranks and roadside tourist traps, the science is anything but funny for those living with the reality of the outbreak.

A Cautionary Tale for a Changing World

Wildlife experts emphasize that, as the climate shifts and insect vectors migrate, zoonotic viral outbreaks among wild animals may become more common, not less. “We’re seeing more overlap between wildlife and human life than ever before,” Dr. Noon warns. “What happens to animals at the edge of our neighborhoods is often a preview of larger environmental issues to come.”

Final Advice—and a Plea for Caution

Authorities stress that the cottontail papilloma virus, though disturbing and tragic for the rabbits it infects, poses no danger to humans at this time. The best course of action, according to CPW and veterinarians nationwide, is observant compassion: watch for signs of disease, protect your pets, and report troubling cases to the proper authorities.

As the “Frankenstein rabbits” of Colorado and the Midwest capture hearts, imaginations, and headlines, one thing is clear—it pays to respect the thin and sometimes fragile boundaries between human lives and the wild, mysterious world still happening at our doorsteps.

If you spot a rabbit displaying abnormal growths, resist the urge to intervene. Let nature—and the experts—handle what centuries of legend have only begun to explain.