A motion attachment device designed to be attached to the keel of a decoy includes a housing or frame that is configured to releasably receive the keel. An actuator coupled to one or more appendages that are attached to the housing or frame to move the one or more appendages to impart a realistic motion to the decoy. The same motion attachment device can be attached to different decoys at different times and can be used with a variety of interchangeable appendages to simulate at least one of a swimming motion, a wing flapping motion, bobbing motion, and feeding motion.
