Jumping into the world of bullfrogs, we find the largest frog in North America! These amphibious showstoppers have an olive green to brown back and sides with a whitish belly spiked with grey or yellow. They have powerful legs perfect for leaping and swimming, large round eyes ideal for spotting prey, and a flat head which measures about half the length of their body. An interesting trait of theirs is their external eardrum, or tympanum, which tells you the bullfrog's gender; if it's bigger than the eye, it's a male.