A firearm rear stabilizing crutch is disclosed having a shaft with a proximal end and a distal end, and an underarm firearm support on the proximal end of the shaft. The underarm firearm support has a support base with front and rear ends and a top element extending therebetween, with the top element defining a generally curved profile extending from proximate the front end to proximate the rear end. A support nose extends from the front end of the support base, with the support nose defining a recess therein for accommodating a firearm buttstock. The distal end of the shaft is configured to be engaged with the ground when the crutch is being used to support a firearm in a shooting position. Some embodiments of the crutch include integrated storage for the shaft and spikes.