5 Shocking Facts About 'Frankenstein Bunnies': The Real-Life Origin Of The Jackalope

The "Frankenstein Bunnies" are not a myth from a bizarre horror movie, but a genuine, albeit unsettling, biological phenomenon that has been making headlines across North America as recently as late 2025. These creatures, which have been spotted and photographed in states like Colorado and Washington, are wild cottontail rabbits afflicted with a virus that causes grotesque, horn-like tumors to sprout from their heads and bodies. The alarming appearance has earned them a host of viral nicknames, including "demon rabbits" and "zombie rabbits," but the scientific explanation is far more fascinating than any folklore. This condition is caused by the Shope Papillomavirus (SPV), a well-documented pathogen that has been studied for nearly a century. While the sight of a rabbit with multiple dark, keratinous growths is certainly shocking, the recent flurry of social media posts and news reports, such as those coming from Fort Collins, Colorado, and Seattle, Washington, underscores a renewed public curiosity about this rare but real-life monster.

The Disturbing Biology: What Causes the 'Horns'?

The unsettling appearance of the Frankenstein Bunny is a direct result of the Shope Papillomavirus (SPV), which is also referred to as the Cottontail Rabbit Papillomavirus (CRPV). This specific virus is a member of the *Papillomaviridae* family, a group of viruses famous for causing warts and tumors in various species, including humans (Human Papillomavirus or HPV).

The Discovery of Shope Papillomavirus

The virus was first identified and studied in the 1930s by American virologist Dr. Richard E. Shope at the Rockefeller Institute for Medical Research. Dr. Shope was investigating reports of "horned rabbits" in Iowa and Kansas. His research on the tumors of the Eastern Cottontail Rabbit led to the isolation of the virus that now bears his name. This discovery was a landmark in cancer research, as it was one of the first viruses definitively proven to cause tumors in mammals, providing a foundational model for understanding viral oncology.

How the Tumors Develop

When a rabbit is infected with SPV, the virus targets the epithelial cells, particularly those in the skin. The virus's genetic material integrates into the host cell's DNA, causing the cells to multiply rapidly and excessively. This unchecked growth leads to the formation of large, black, or dark-colored keratinous tumors (warts or papillomas). These tumors are made of keratin, the same protein that makes up hair, skin, and fingernails. They are typically hard, rough, and can grow to resemble grotesque, branching horns, primarily on the rabbit's head, face, and neck, though they can appear anywhere on the body.

Transmission and Susceptibility

The primary host for the Shope papillomavirus is the North American Cottontail Rabbit (*Sylvilagus floridanus*). The virus is typically transmitted through direct contact with infected skin lesions or, more commonly, by biting insects like ticks and fleas that act as mechanical vectors. While the tumors themselves are generally non-malignant (benign), the condition is far from harmless to the rabbit. The growths can become so large and numerous that they obstruct the rabbit's sight, making it impossible to evade predators. Crucially, the tumors can also grow around the mouth and jaw, preventing the rabbit from feeding or drinking, which often leads to starvation and dehydration.

5 Shocking Facts That Define the Frankenstein Bunny

The phenomenon of horned rabbits is a perfect blend of science, folklore, and viral media. Understanding the key facts separates the scientific reality from the sensationalized headlines.

Fact 1: They Are the Real-Life Inspiration for the Jackalope

For centuries, tales of rabbits with horns—known as the Jackalope in North American folklore, or the Wolpertinger in Bavaria—have existed. The Jackalope legend, popularized in Wyoming, describes a fierce, antlered rabbit. Researchers and scientists now widely accept that sightings of rabbits infected with SPV, sporting their dramatic horn-like tumors, are the most probable source for these enduring myths. The bizarre growths seen on these cottontails provided a tangible, if misinterpreted, basis for the fantastical creature.

Fact 2: The Virus is Named After a Cancer Research Pioneer

As noted, the virus is named for Dr. Richard E. Shope, who made a monumental discovery in virology and cancer research. The isolation of SPV demonstrated that viruses could cause cancer in mammals, which was a revolutionary idea at the time. The virus became an essential animal model for studying the mechanisms of viral carcinogenesis and the development of papillomavirus vaccines, including the human HPV vaccine.

Fact 3: Recent Sightings Have Gone Viral Across the US

In recent years, the "Frankenstein Bunny" has experienced a resurgence in public awareness, largely due to social media and local news reports. In 2025, reports of "demon rabbits" in Fort Collins, Colorado, and isolated sightings in Seattle, Washington, and Northern Wisconsin, brought the issue back into the spotlight. The combination of a visually shocking image and a catchy, unsettling nickname has driven significant online discussion, turning a regional wildlife disease into a national curiosity.

Fact 4: The Growths Can Be Fatal, But Not Always

While the tumors can look terrifying, the Shope papillomavirus infection is often self-limiting in many rabbits. The rabbit's immune system can sometimes suppress the virus, causing the tumors to regress and disappear. However, in cases where the tumors are numerous or grow strategically (blocking the eyes, nose, or mouth), the infection is indirectly fatal. The rabbit dies not from the virus itself, but from secondary effects like starvation, predation, or secondary bacterial infection within the lesions.

Fact 5: It Poses Minimal Risk to Humans and Domestic Pets

A common fear when these sightings go viral is the risk of transmission to humans or domestic pets like dogs and cats. Wildlife experts and veterinarians, including those from the American Veterinary Medical Association (AVMA) and the Washington Department of Fish and Wildlife, consistently state that the risk is extremely low. SPV is highly species-specific; it primarily affects the *Sylvilagus* genus of rabbits and snowshoe hares (*Lepus americanus*). While caution is always advised, humans cannot contract the "horned rabbit" disease from an infected animal.

Topical Authority: Key Entities and Terminology

To fully understand the world of the Frankenstein Bunny, it is essential to grasp the core scientific and historical terminology. The topic is rich with interconnected biological and cultural entities.

Scientific Entities:

• Shope Papillomavirus (SPV): The causative agent, a DNA virus.
• Cottontail Rabbit Papillomavirus (CRPV): The alternative, descriptive name for the virus.
• Keratinous Tumors: The hard, horn-like growths composed of keratin protein.
• Papillomaviridae: The family of viruses to which SPV belongs.
• Viral Carcinogenesis: The process by which viruses, like SPV, induce tumor formation.
• Eastern Cottontail Rabbit (*Sylvilagus floridanus*): The primary natural host for the virus.
• Mechanical Vector: Biting insects (like ticks and fleas) that transmit the virus between hosts.

Cultural and Geographical Entities:

• Jackalope: The mythical horned rabbit of North American folklore, directly inspired by SPV-infected rabbits.
• Wolpertinger: The German mythical creature similar to the Jackalope.
• Fort Collins, Colorado: A recent hotspot for viral sightings and media reports.
• Seattle, Washington: Another location where recent sightings have garnered media attention.
• Richard E. Shope: The virologist who discovered and isolated the virus in the 1930s.
• American Veterinary Medical Association (AVMA): Source of expert information on the low risk to domestic animals.

The story of the Frankenstein Bunny is a compelling example of how a strange natural phenomenon can inspire centuries of folklore and, eventually, become a crucial subject in modern medical science. The next time you see a picture of a "demon rabbit" online, you'll know the truth: it's not a monster from a lab or a mythical beast, but a real cottontail rabbit struggling with a virus that changed the course of cancer research.