You can use #monster while riding a steed with a breath weapon to make it use its breath weapon. You get prompted for the direction.

Using #monster when polymorphed into a demon allows you to call for hell-p from other demons directly, without needing to hit an enemy in melee. This uses up some Pw. It may not work 100% of the time, but will cost Pw regardless of whether or not it works. Another possible restriction is that you need to be next to a known enemy for it to work.

If polymorphed into a voluntarily exploding monster (e.g. a sphere or light), the player can #monster to explode without actually attacking anything. (You can already do this by forcefighting thin air, so this would just add an additional way to do it and a prompt when you polyself.)

Using #monster while polymorphed into a queen bee makes you secrete a lump of royal jelly. For balance, this should cost a lot more nutrition than the royal jelly contains, or have some other limiting method so you can’t use an indefinite food source to produce indefinite royal jelly.

The scroll and spellbook of web allow you to fire a web projectile (which would work similarly to a venom projectile, probably also being in VENOM_CLASS) or beam in a direction. If it hits a wall, it creates a web on the last non-wall space; if it hits a monster it creates a web on the monster’s space and immediately entangles it. If it goes far enough without hitting anything, it creates a web at the end of its range.

Giant spiders should possibly also be able to shoot a web like this, and if so the player should be able to do it via #monster when polymorphed into one.

When polyselfed to foocubi of the appropriate gender, #monstering will seduce (i.e. de-robe) @ monsters.