Abstract: Apparatus for chunking wood slabs and the like. The apparatus includes a rotary drum mounted on a frame for powered rotation thereon. The drum carries two linear arrays of teeth at diametrally opposed drum positions, the teeth in the two arrays being disposed at alternate, axially offset positions. A notched anvil in the apparatus is mounted on the frame for reciprocating between first and second positions where the anvil is positioned to intermesh with one and then with the other tooth arrays. The anvil is shifted between its first and second positions, in synchrony with drum rotation, by a pair of flanges carried at opposite ends of the drum, parallel to one another and in planes non-normal with respect to the drum's rotational axis, and a pair of rollers mounted adjacent opposite ends of the anvil for engaging the inner surfaces of the associated flanges.