Michael Messenger, from Ipswich in Queensland, Australia, was sitting in his yard when the strange creature emerged from the bushes.
“It was normal size, but smaller than a hand,” Messenger told Newsweek. “It just hopped at a normal toad speed.”
“It had an extra part. It just looked like a normal toad, except it had a leg as a tail,” Messenger told News Australia. “I don’t think [the extra leg] has any function. It just drags behind, but it looks weird.”
“I have seen toads with five legs before. It’s very rare,” toad researcher Rick Shine, from Macquarie University in Sydney, Australia, told ABC News.
“In the course of research, we’ve handled many thousands of toads. I’ve probably seen it two or three times myself.”
In this case, Shine said that the toad had been injured when it was a tadpole, causing one of the limbs to develop into two.
“While it’s an embryo, the limb bud could get split into two and end up producing two legs,” Shine said. “It’s something that happens with frogs more often.
“Other animals have babies in utero or in eggs so they’re protected, but tadpoles aren’t. The tadpole is swimming around in the open, and usually one parasite attacks the tadpole and injures the limb bud, and you end up with two legs.”
Bullfrogs in the western U.S. have been seen to develop extra limbs because of infection by the flatworm parasite Ribeiroia ondatrae. This larva burrows into the tadpole, forming cysts around the frog’s developing limbs and altering their development.