I was playing yesterday with some friends and noticed on the flip side of the dragon bile token, there is burning dragon bile (i.e. Dragon Fire).
We thought, "What a waste of a token." Then we thought how interested it could be if Dragon Fire would burn for 1d3 (or heck 1d6) rounds preventing anything from passing.
If it were 1d3 rounds....it would kill any zombies you could lure in via noise, but no one would get any XP for those. I'm not sure if this would enhance the game or not. Usually, as a friend pointed out, you're running away from things...so leaving a fire behind you might be more of a help than a hinderance.