Colorado River Toad Incilius alvarius/ (prev. Bufo alvarius)

The Colorado River Toad, previously called Sonoran Desert Toad, is the largest native toad in North America. Native to northern Mexico and southwestern USA, it can grow to nearly 20cm head/body length. It excretes a toxin from glands on its back strong enough to kill a dog-sized predator and have psychoactive effects on humans.