If you fall through a hole or trap door onto a level, and there is a trapper or lurker above in the area you are eligible to arrive in (because some levels constrain the region you can arrive in), you automatically land on its space and get instantly engulfed by it (with a message stating as much). This is because the monster was lurking by the shaft in order to catch easy prey.

Make trappers and lurkers above mindless, so they’re not trivial to find and avoid with telepathy.

Trappers’ and lurkers’ above digestion happens much more quickly than purple worms, on a shorter timer. As it stands, most digestion attacks aren’t very threatening as an instadeath because the player almost always has time to kill the digester.

For that matter, all digestion attacks should probably be accelerated somewhat, even those of purple worms.