2. The adult length of bullfrog is generally between 70- 170 mm, and the longest is over 200 mm. It is one of the largest frogs in the world. The skin is usually smooth, without dorsal folds, and the snout is wide and round. Women's eardrums are about the same size as their eyes, while men's are obviously larger than their eyes. A fold from the back of the eye around the eardrum to the armpit, especially in men. The fourth toe is too long, and the webbed toes can't reach it at all. Due to different regions, body color often changes greatly. The back turns from green to brown, but most of it is green. Usually mixed with brown spots, sometimes mixed with gray or brown mesh patterns. The ventral surface is white, sometimes with gray spots, and the adult throat often has yellow stripes.