Abstract: An interchangeable chipper tool attachment for a hog allows a hog machine to operate as either a hog or a chipper. An operator of the hog machine can remove hammer tools used in the hog and replace them with the chipper attachment. The chipper attachment includes knife receiving area, a knife support receiving area, and a fastener portion for mounting the tool holder to rotor disks on the rotor assembly of the hog machine. A knife assembly, including a chipper knife, is coupled to the tool holder at the knife receiving area and points in the direction of rotation of the rotor. A knife support block supports the chipper knife and is coupled to the tool holder at the knife support receiving area, a lateral face of the tool holder adjacent to the knife receiving area. When mounted in an interleaved fashion between the rotor disks of the rotor assembly, the chipper knife rotates in a circular path and produces chips by cutting wood waste against an anvil on the hog.