The Drinker (Euthrix potatoria) is a moth of the family Lasiocampidae. It is found in Europe.Males and females differ in their general colouration, as illustrated, but are generally brown or orange-brown. The pale yellow male form pallida is frequent in the Fens, but rare elsewhere.
The wingspan is 45–65 mm. The moth flies from June to August depending on the location.
The larvae feed on various grasses and reeds. The larvae is distinctive with a "horns" on both the head and back. The caterpillar is also hairy. The caterpillar gives the species it's name, as it is said to drink the dew drops off blades of grasses. The larva feed on various grasses and plants including Common Reed and Canary Grass.