The toadfish croaks like its amphibian namesake but typically looks more like the seafloor surroundings where it lies in wait for prey. The fish also has a remarkable tolerance for ammonia, 10 to 20 times greater than that of a human. Scientists studying how the toadfish survives such toxins say the humble animal could someday help produce medical treatments for human ailments including liver disease, stroke, heart attack, and brain injury.

(From National Geographic)