[1] Turning the corner at the end of the passage way, the grue comes face to face with a herd of angry mammoths
[2] Search for stupid adventurers stumbling around to eat.
[3] Punch through a wall like the Kool-Aid Man and eat the poor kobolds on the other side.
[4] Evolve above your brethren and become a godlike grue-man.
[5] Using your hypersensitive grue-smell, follow the peculiar smell of tobacco burning to its source.
[6] Eat one if your legs, realise your mistake and screech for help.
[1]
They say that curiosity killed the cat. Felines are indeed tasty, if a bit stringy, so the grue goes to the exit of the dungeon. Well, it's less of an exit and more of a hole that leads into the higher levels of the dungeon. The inhabitants of said dungeon never bothered to close it off, because they knew that anybody who planned on using the hole as a secret exit would find themselves rather quickly inside the stomach of a very hungry grue.And the grue wouldn't have it any other way.
It is night time outside. The grue doesn't like being outside, even at night, because the moon can still shine brightly enough to temporarly blind it. However it is new moon that day, so all is good.
Using its keen eyesight, the grue could make out a group of mammoths in the dark. The grue liked mammoths. Lots of fur, but enough meat to last it for a week or two.
Behind them it spotted more creatures. It was a kobold hunting group, each riding a sabretooth tiger. Why aren't any of the cats dead? The grue felt so betrayed by the idiom.
What it didn't know is that, at the same moment, a kobold princess would be weeping over the grave of her precious kitten.
While you're discussing the benefits of wearing underwear, I'll be over there, building snowmen. Call me when you're done.