Frog (Books)

Frogs are mentioned in the How to Train Your Dragon Book series, but not actually seen.

Description
Frogs (Order Anura) are amphibians who do not have a tail in their adult form, though larval stages - known as tadpoles - typically do have tails for swimming. Despite being bound to water or moist habitats, frogs occur worldwide with the exception of the Arctic, Antarctica, and true deserts. Though the greatest species diversity occurs along the equator in rain forests, frogs that live in cold and dry climates have many adaptions for survival. Many species are able to enter a suspended state of torpor or hibernation. During winter in many areas, frogs may enter hibernation in a burrow, in mud at the bottom of a pond, or under leaf litter. Other frogs can even be frozen, keeping vital organs from freezing by an excess accumulation of glucose. Some frog species in dry climates undergo aestivation (hibernation in hot weather) after burrowing into the earth and adapting physiologically.

Function
In the Book series, frogs are mainly used as a derogatory descriptor for dragons.

In reality, the primary use of frogs is as a food source for humans. They are also used in medical research and medicine.

Appearances
How to Train Your Dragon Frogs are mentioned multiple times, mainly for describing Toothless in a negative light.

"Something that makes a Monstrous Nightmare look like a flying frog!"

- Fishlegs hoping Hiccup grabbed a "cool" dragon from the Dragon Nursery

"What is it, Hiccup? A brown bunny rabbit with wings? A flower fairy? A fluffy flying frog?"

- Snotlout describing Toothless