Mutant deer with horrifying tumor-like bubbles showing signs of widespread disease spotted in US states

Warning: Graphic imagery ahead

It looks like the Umbrella Corporation has been tinkering in real life, as a spate of 'infected' animals has us thinking of Resident Evil.

While we're thankful the bioweapons of Capcom's video game series are just monstrous pieces of fiction (for now), some horrifying afflictions conjure up images of Tyrants, Lickers, and Crimson Heads.

There's been a recent run of concerning animal outbreaks, and in the aftermath of Frankenstein rabbits, we then reported on zombie squirrels spreading across the USA.

Some of the scariest things can be based on real-life science, but alongside World War Z's zombie outbreak becoming a potential reality, Naughty Dog's The Last of Us and HBO series of the same name tackle the science of the cordyceps infection.

What is deer fibroma?

Animal authorities across the USA are now keeping their eyes out for 'mutant' deer amid a spike in cases reported in the likes of New York, Pennsylvania, and Wisconsin.

There have been multiple social media posts showing these mutant deer with massive growths and tumors hanging off them.

In reality, this is deer fibroma, which is also known as cutaneous fibromas, fibromas, fibromatosis, or deer warts.

The virus is nothing new, but it is hard to control, especially in the summer months. Deer fibroma is typically spread through mosquitoes and ticks that've bitten infected deer. Remembering that insect populations boom in warmer periods, the deer don't stand much of a chance.

The Washington Department of Fish and Wildlife warns: "Papillomas are most frequently seen during the late summer and into the fall, probably due to increased biting insect activity during this time of year."

A July 2025 Reddit thread had someone sharing stills from a deer caught on their backyard camera, with the OP questioning whether it was sporting a gunshot wound on its face. Instead, the comments were full of people reiterating its deer fibroma.

Can deer fibroma affect humans?

Speaking to FOX13, wildlife veterinarian Dr Kristin Mansfield said that while these warts are typically harmless and will clear up on their own, there can be complications: "Occasional individual animals — they will get really massive infections with these warts.

“We suspect that these deer have some kind of immuno-suppression problem or their bodies aren't able to fight off the virus that causes the warts."

Much like in humans, the warts can be spread through direct contact, like deer sharing the same rubbing post or being in close contact with each other at feeding spots.

Still, Mansfield says the warts can be cut off the skin, and the meat is still good for hunters to eat.

Papillomaviruses aren't unique to deer, and in humans, they can manifest as common, plantar, or genital warts, with some strains even being linked to throat and cervical cancers.

Thankfully, deer warts are specific to that species, meaning humans and other pets can't be infected due to the way in which the virus attaches to cells. Then again, if you have any pet deer, you might want to remain vigilant.