A toad found in a state forest in Connecticut startled researchers in the field because it had no face.

The amphibian, an adult American toad, was hopping into the researchers’ feet and other objects repeatedly while they were collecting information about newts. Jill Fleming, a herpetologist and student at the University of Massachusetts at Amherst, took notice. She and her colleagues took a closer look at the toad, and they were surprised to seethat its eyes, nose, jaw, and tongue were completely missing.

She says the reason why the toad is missing its face is a mystery, though there are a few possible explanations.

“My initial thought, which I still believe is a likely explanation, was that the extensive injury was inflicted by one of the toad’s many natural predators during hibernation (for example, garter snakes or American mink),” she says. “For whatever reason, the predator did not finish the job and the toad was able to become active again on that early spring day—amphibians are incredibly resilient.”

Herpetologists on Twitter also thought it could be the result of parasitism by a toad fly, though Fleming thinks it’s less likely.