Goblet-shaped, leathery, brown. Grow in clusters on small to medium-sized decaying branches of hardwoods. March–May. Cup closed when immature, then opening to a deep "urn"; inner and outer surfaces are dark brownish black; texture tough and rubbery. Stalk thick, with sides equal; blackish; with a dense covering of hairs. Spore print blackish brown. Spores magnified are elliptical, smooth.
Lookalikes: Hairy rubber cup (Galiella rufa) fruits July-September (not in spring), and its inner surface is a lighter, chocolate brown. Before the devil’s urn has opened, it may look like dead man’s fingers (Xylaria polymorpha).