A tracking device is configured to detach from a launched projectile to remain in an animal when the projectile proceeds completely through the animal. The tracking device can be attached to the end of an arrow shaft and provide the nock of the arrow. A decelerator such as a barb, an offset fin, or a reverse helical projection is provided to aid in detachment of the tracking device from the arrow shaft as it passes through the animal. The tracking device remains embedded in the animal so that the animal can be tracked instead of the arrow.