According to the AmphibiaWeb database there are currently 6,644 frogs and toads in the world. The variety of frogs is astonishing!
The largest frog recorded is the Goliath Frog, growing to 3 kilograms! It is found in Cameroon and Equatorial Guinea in Africa. Unfortunately, these big guys are endangered due to habitat loss and over-collection for the food and pet trade (Photo: . https://au.pinterest.com/pin/330310953892352940/)
On the other end of the spectrum, here is a photo of the smallest frog Paedophryne amauensis recorded so far. They are the smallest vertebrate animal recorded (http://news.nationalgeographic.com/news/2012/01/120111-smallest-frogs-vertebrates-new-species-science-animals/). They are tiny - about 7.7 mm long - and seem to live solely amid leaf litter on New Guinea's rain forest floor. These little guys have adapted to eat very small insects like mites and camouflage well in the leaf litter.