Michael Bogan was on a night hike in Arizona's Sabino Canyon Recreation Area when he looked down and saw a Sonoran Desert toad.

The biologist typically stops and looks at every amphibian he sees, but as he moved his headlamp toward this one, he noticed something odd.

“All of a sudden, I was like, What is that hanging out of its mouth?” says Bogan, an assistant professor at the University of Arizona. (See a picture of a toad eating a bat.)

Black, sticklike appendages protruded from the toad’s face—an animal was still alive, wiggling inside. He realized the toad was attempting to gulp down a live western desert tarantula.

Tarantula Escapes From Toad A western desert taratula flees from a Sonoran desert toad in a recreation area outside Tucson, Arizona.

Bogan leaned down and took some pictures of the toad, waiting for the unlucky arachnid to meet its fate. But the tarantula wasn’t ready to go peacefully into the night.

As the spider struggled, Bogan witnessed the toad close its eyes, wincing with pain, and its elastic throat stretched out in the shape of spider fangs. It appeared the tarantula was trying to bite its captor from the inside.

Unappetizing Tarantula

“We don’t know whether the tarantula released any venom or not, but it wouldn’t have to,” says Jerome Rovner, an arachnologist and emeritus professor at Ohio University, who saw pictures of the incident. “The urticating hairs are all that’s needed for it to defend itself.” (See pictures of colorful tarantulas discovered in Brazil.)

World's Weirdest: World's Biggest Spider With a leg span nearly a foot wide, the goliath bird-eater is the world's biggest spider. And it has a special defense mechanism to keep predators from considering it as a meal.

Urticating hairs, bristly and very sharp, cover a tarantula’s abdomen and legs and make the spider very unappetizing for any potential predator.

“It would be like trying to eat fiberglass,” says Rovner.

Tarantulas sometimes “dry bite” to scare away predators, without releasing venom that the arachnids save for their prey, he adds.

But whether the toad was stung or just bitten, it must have been very uncomfortable. “The toad was likely getting a double dose,” says Bogan.

Spider's Daring Escape

The toad, which swallows its prey whole, likely "did not have an anticipation of what a mouthful of tarantula would mean,” says Rovner.

After getting poked with both tarantula fangs and bristles, the toad opened its mouth to release its prey. The arachnid skittered away, covered in slime and gastrointestinal juices, with two of its legs seemingly injured or impaired. (See seven spider and bug myths squashed.)

View Images The tarantula escaped with two injured legs—but may be able to survive, experts say. Photograph by Michael Bogan

Both experts noted that spiders can often live with multiple missing legs. As for the toad, it seemed no worse for wear, albeit still hungry.

“It’s never the end until it’s really the end,” says Bogan, reflecting on what he had witnessed.

“Even when you’re halfway down the mouth of a toad, you still have a chance.”