Colorado Parks and Wildlife officials have identified the cause as shope papillomavirus, a rabbit-only virus with no cure that produces wart-like tumours known as papillomas, particularly around the face and head of cottontail rabbits, 9NEWS reports.

FORT COLLINS, Colo. — Rabbits that look like something out of a nightmare are being seen in Colorado. Bunnies with what appear to be tentacles growing from their faces are hopping around Fort Collins, KUSA reported. One person described the rabbit as having “a scabbiesh-looking growth over their face.” https://t.co/fkeN8gW3vO