Lycoperdon pyriforme

Common Name: Pear-shaped Puffball
Description: Fruit body 1.5-4 cm across, 3.5 cm high, subglobose to club- or pear-shaped, attached to the substrate by prominent mycelial strands. White when young, then soon pale yellowish buff or gray-brown; outer layer of scruffy spines, warts, or granules, inner wall becoming smooth and papery, opening by an apical pore.
Habitat: in large clusters on decaying wood, logs, etc. Common. Found widespread throughout North America.
Edible: good when young.

Source: Mushrooms of North America by Roger Phillips.