Like frogs, toads are amphibians. They differ from most frogs because they have dry skin, warts, crests behind the eyes, and parotoid glands. The parotoid glands produce a poisonous secretion that helps the toad defend itself from predators.

This substance, called a bufotoxin, can cause death in small animals and allergic reactions in humans. Toads have other ways to avoid being eaten too. If they’re brown or green in color, they can blend into their surroundings and escape detection. If brightly colored, they warn predators to stay away because they’re poisonous. Toads also puff up their bodies in an attempt to look bigger and inedible if a predator is nearby.

The smallest North American toad is the oak toad (Bufo quercicus), which reaches a length of only 1.3 inches (3.3 centimeters). Cane toads (Rhinella marina) are the largest toads and grow up to 9 inches (23 centimeters) in length. But a massive cane toad caught in Australia, nicknamed “Toadzilla,” has been described as the size of a small dog!