The biggest kind of frog is the Goliath frog (Conraua goliath).
They come from Cameroon in West Africa. Their bodies can reach the size of
nearly a foot (30 cm) long.(remember: their legs are also AT LEAST that long!!!!)This image was found in Inky's Linkies: Herp Gallery
Another kind of really big frog are called Cane toads,
(also called "marine toads" or "giant toads"). Adult marine toads generally range in size from 6-9 inches
(15-23 centimeters), but may get larger.
Some species of bullfrogs get pretty big too.