Drowsy-Tipped Dragonmice are a species of Nanodragon seen in The Incomplete Book of Dragons and also had a small pictorial cameo in How to Fight a Dragon's Fury.
Physical Appearance
Dragonmice are, as nanodragons are, extremely tiny — the size of insects. They have a large spaded tail, two pair of legs, and a pair of legs. Their notable feature is their long, rabbit-like ears, which appear to nearly be as long as their bodies (not including the tail).
Behavior
Drosy-Tipped Dragonmice are extremely active during their waking hours, appearing as only a blur as they catch and eat their prey (presumably bugs). However, a Dragonmouse's waking hours are only 15 minutes. For the rest of a 24 hour period they are fast asleep.
Like all Nanodragons, they remained uninvolved during the Dragon Rebellion.
Appearances
The Incomplete Book of Dragons
Dragonmice are illustrated and named in this reference book, in the section discussing Nanodragons.
How to Fight a Dragon's Fury
In this final Book of the series, the Dragonmouse makes a small appearance along with other Nanodragons, when Ziggerastica appears with his Nanodragon kingdom to help Hiccup obtain the crown of the Wilderwest.