Carlos Jared/Butantan Institute

The next time you're strolling in a Brazilian jungle, and you see a cute frog, and you want to pick up that frog, don't! Because it might be Bruno's casque-headed frog, a fairly normal looking frog who can stick you with poison using the sharp spines on his head, and one gram of that poison is powerful enough to kill 80 humans.

Bruno's Casque-headed Frog
Carlos Jared/Butantan Institute

Brazilian scientist Carlos Jared¬†learned that the frog was venomous during a recent expedition, when he also learned that the Greening's¬†frog is (less) venomous‚ÄĒbecause he was himself struck and poisoned by the frog. CBC News reports:

Carlos Jared, a researcher at Instituto Butanan in Sao Paolo, was collecting frogs in a forest Goytacazes National Reserve in southeastern Brazil when one of them head-butted him, jabbing its spines into his hand. That caused 'intense pain radiating up the arm, lasting about five hours.'

Jared and his team discussed their findings in an article in Current Biology this week.


Greening's frog
Carlos Jared/Butantan Institute

CBC explains that these are the first two frogs to be classified as venomous, rather than poisonous. The difference is that venomous frogs strike, while poisonous frogs excrete poison.

Danielle Wiener-Bronner is a news reporter.