With a penalty to your next combat due to distraction, a la Munchkin?
Actually some 1-time penalties in JJ's list of punishments wouldn't be a bad idea. He currently has corrosion and weakening that are permanent, mana burn and poison which last until you level up, and health drain which can be dealt with by exploring (but is pretty devastating if you also get hit by poison or if you're a late worshipper and exploration space is limited). Having some one-time effects that don't rack up long-term penalties would round things out a bit.
A Goomba Berserker?! How'd you get that?
Secret unlockable monster race. Didn't you know about it? Of course, the Goomba Crusader is the best.