Withermoth

''The withermoth is a curious phenomenon. It is tremendously large for an insect, and somehow its size allows it to expel a charging force when attacked. For this reason, few have survived to study it in great detail, including many notable academics. In fact, please do not inquire further upon this subject.'' - Abd al-Hazir

Withermoths appear in  and  of Diablo III, and are one of the beast enemies representing natural, hostile wildlife rather than demon-corrupted animals.

In-game
The Withermoth is only encountered after killing the Spider Queen and before finding King Leoric's Mansion in Act 1, making opportunities to fight it rather sparse. However, in Act V, one may encounter them in caves beneath the Blood Marsh and Paths of the Drowned.

While relatively weak, Withermoths use a lightning attack which deals a good amount of damage, and appear from the ground, as though burrowed into it in ambush, making them a foe easy to be surprised and hurt by. Their hideouts are visible and can be spotted on time, but the moths within are immune to attacks until they emerge.