Antler fungus

Xylaria hypoxylon is a species of fungus in the family Xylariaceae. It is known by a variety of common names, such as the candlestick fungus, the candle snuff fungus, carbon antlers, or the stag's horn fungus. The fruit bodies, characterized by erect, elongated black branches with whitened tips, typically grow in clusters on decaying hardwood. The fungus can cause a root rot in hawthorn and gooseberry plants.

Source: Wikipedia