The U.S. National Park Service (NPS) is urging people not to lick the Sonora Desert Toad, CNN reports.

The NPS has warned passersby to be cautious of the Sonora Desert Toad, also known as the Colorado River Toad.

It is one of the largest toads found in North America, measuring up to 7 inches.

But toads native to the American Southwest also boast another unique feature: according to the NPS, they have prominent parotid glands that secrete a potent toxin. The parotid glands are located just behind the toad's eyes.

These toxins can make people sick if they touch or lick the toad.

Therefore, people were advised to refrain from "licking" the toad.

Toxins from toads are especially dangerous to other animals. According to the Arizona-Sonora Desert Museum, the toxins produced by a single Sonora Desert toad can be enough to kill an adult dog.

But people use its toxins for other purposes. When smoked, the toxins are a powerful psychedelic. Smoking Sonora desert toad excreta causes euphoria and severe auditory hallucinations.

According to the Zoo, possession of toad venom, known as bufotenin, is illegal in California.