What should I do now?!? That gnoll is blocking the way out.
The gnoll is not facing you.
If no exclamation mark (yellow-red) was shown, you may be able to tap the clock and wait for them to head back out.
You could fly to lower-left corner to be out of sight until they leave.
Also, always convert a teleport-scroll to purple diamonds, for this very eventuality.
Use your range to take him out. Even when he’s enraged, he won’t go on the traps, so stay where you are and use your wands/throwables. You will end up taking damage from 2 traps, but it’s no big deal, you got the hp for it.
Got any invisibility potions? Fear stones? Scrolls?
Yeah, I would probably use a fear stone if I had one. Going back and using a fadeleaf would be a cheaper option but might result in jumping from the fire and into the frying pan.