I have not seen one of these before and didn't expect to find them (and hundreds of former tadpoles) in a pond at a nearby small park. According to Siri, they are Colorado River toads. Per Wikipedia, "The Colorado River toad (Incilius alvarius), also known as the Sonoran Desert toad, is a toad species found in northwestern Mexico and the southwestern United States. It is well known for its ability to exude toxins from glands within its skin that have psychoactive properties. The Colorado River toad can grow to about 190 millimetres (7.5 in) long and is the largest toad in the United States apart from the non-native cane toad (Rhinella marina)."
