National Park Service is asking the public to not lick the Colorado River Toad. It's one of the largest toads in North America and also releases a strong poison. The poison released on the toads' skin is said to be enough to kill a grown dog.
The frogs' poison if ingested by a human can make them extremely sick and some use it as a psychedelic. According to the Oakland Zoo,
It is illegal to have the poison from the toad, called bufotenin, in your possession in the state of California.