Avena sterilis (animated oat, sterile oat, wild oat, wild red oat, winter wild oat; syn. Avena ludoviciana Durieu; Avena macrocarpa Moench; Avena sterilis ssp. sterilis; Avena sterilis ssp. ludoviciana) is a species of grass weed whose seeds are edible. Many common names of this plant refer to the movement of its panicle in the wind.

Avena sterilis is a stout, broad-leaved grass that grows up to 1.5 m (4 ft 11 in) tall. At maturity, it has leaf blades that are up to 60 cm (24 in) long, and 6–14 mm (0.24–0.55 in) wide.

It has an inflorescence that is either an equilateral or a slightly one-sided panicle. The spikelets usually have 3 florets, but can have anywhere from 2 to 5. The spikelets (without awns) are 1.7–4.5 cm (0.67–1.77 in) long; the glumes are 2.4–5 cm (0.94–1.97 in) long.

The florets can either be a straw yellow or slightly reddish in colour. Occasionally, there can be reddish hairs at the base of the floret.

The lemma is usually 1.5–4 cm (0.59–1.57 in) long. The florets are elongate and taper at the top. The two florets closest to the glumes have a twisted dorsal awn that is 3–9 cm (1.2–3.5 in) long.

One can distinguish between the two subspecies, A. sterilis sterilis and A. sterilis ludoviciana, using the size of the reproductive parts of the flower.

A study of 139 populations of A. sterilis L. in Spain revealed 6 varieties based on morphological classifications, though no new subspecies were formally described.

A. sterilis is hexaploid. It is an annual plant, with a life cycle that mirrors many cereal crops. While an individual plant is capable of producing as many as 200 seeds, the average seed production of a single plant is 13-21 seeds. Seeds regularly live in the soil for upwards of two years, and can survive for as many as 5 years prior to germination.