Mimics should try to impersonate containers more frequently than they do. There are a few proposals for accomplishing this in the Dungeons of Doom:

• Have a special case that generates a mimic in each room with very low probability per room; if a mimic does generate it will always imitate a chest or large box.
• When a large box or chest is generated in a room during level creation, there is a small chance it instead becomes a mimic imitating that type of container, replacing the box. However, the chest contents must be carefully discarded to unmake any artifacts that happened to generate inside it.

Both of these only happen on levels where the mimic being generated is within its ordinary level difficulty range.

New type of lamp, lava lamp, which only randomly generates in Gehennom.

Muzzle: a tool that can be applied to an adjacent hostile monster to attempt to muzzle it. Success depends on your Strength and Dexterity, and if you do muzzle the monster, any bite attacks it has are prevented from happening.

New artifact dagger that, when thrown, teleports you to wherever it lands. Some attributes it might have:

• If it lands in liquid, you could be teleported to the nearest available land, or to the liquid square, where you promptly fall in, possibly drowning or burning up. A nicer implementation could prevent it from landing in liquid in the first place, teleporting itself elsewhere, since it would be tough to get out.
• If it falls to another level, you levelport to where it falls.
• If a monster somehow eats it, you teleport inside its stomach, killing it (unless it’s capable of engulfing you, in which case you teleport to being engulfed inside it).
• A side proposal is that instead of a dagger, this is an artifact gem.

Replace the amulet in the portal-less fake Wizard’s Tower with a magic marker.

Themed room named “Home Sweet Home” - one that a former adventurer has retired in and made their own. There is a peaceful player monster inside, and some trappings of home life such as a sink, a chest, food, and so on. If beds as a dungeon feature exist, there is also one of these.

Add a themed room commemorating the long-lived tactic of pudding farming. It has the following properties:

• It is a huge room, possibly a variant of the “Huge room” themed room with no subroom.
• On one space in the middle of the room is the pudding farmer, a random player monster.
  • They generate at level 15-30, as they do on the Astral Plane, but don’t have the same equipment as they would get on the Astral Plane, just the regular gear a player monster would get. Possibly some nicer gear under the assumption they’ve farmed it off the puddings.
  • They are hostile to the player, unless of the same role, in which case they are peaceful.
  • The pudding farmer also carries a thoroughly rusty -3 knife or stiletto, their Puddingbane, though it is not named as such.
  • Messages and farlook show their name as having replaced their rank title with “Pudding Farmer”, e.g. “Fred the Pudding Farmer”.
• The remaining spaces in the room have some reasonably high chance of spawning a black pudding, with varying degrees of reduced current and maximum HP.
• There may be a sink somewhere on the room’s floor, from which the initial pudding came.
• No globs of pudding on the floor from already-killed puddings; the thematic thing would be to have pudding corpses, which no longer exist in vanilla. Globs would imply the player monster has been pudding farming in NetHack 3.6 or later, which doesn’t make much sense.
• The minimum level difficulty of this room is 4, though that seems awfully low given how dangerous it’s likely to be. It could be based on the difficulty of black puddings, such as the difficulty of a black pudding + 3.
• One option to cut down on the gimmickiness of it is to have the corpse of a player monster, possibly with some gear, but not the player monster themselves, implying they slipped up and fell victim to the puddings.
• Since it was possible to pudding farm brown puddings in earlier versions of NetHack, there could be some chance that this room consists of brown puddings instead, which could then appear at a slightly lower difficulty and would lack a sink. Though this would be strange in the above case of there being a corpse rather than a player monster, since brown puddings cannot deal damage (maybe they choked?)