Building 10 rooms

TWO-HEADED SLIME: PLANT
SHIELD DRAGON: MONSTER
PSEUDO-TOAD: VERMIN
BRASS SATYR: HUMANOID
SIEGE ORB: BOSS
TOTEM RAY: CRITTER

I
| |
F--A--B
| | | | | |
E--D--C--J
| | | |
H--G
Room A.
Inverted ziggurat - steps going down to bottom of room, altar to dungeon god at lowest point. HOGGWIND the SINGING CHAMBERMAID is tied to altar with BRASS SATYRs preparing to sacrifice them. Everything exactly as it seems.
Room B.
SIGHT: Room is part of ancient mansion, walls are rotting wood.
Old wooden chest, given wide berth by nervous, prowling BRASS SATYRs who are 100% certain it's a mimic. 20% chance this is true. Key to chest, even if it's a mimic, is clutched in the hand of the top half of a skeleton in room G. Chest contains reasonable amount of gold, partially-chewed WIG OF COMMAND (operates at half efficiency until repaired), gnawed bottom half of skeleton. Possible if chest not mimic that it will follow PCs around dungeon fucking w/ them.
Room C.
Apparently empty room w/ very high ceiling. Vibrations in floor disturb the nests, cause rain of PSEUDO-TOADs. Safe to move around edges of room.
Room D.
Single enormous TWO-HEADED SLIME growing up towards skylight in very top of room. PSEUDO-TOAD nesting in roots.
Room E.
SIGHT: The roots of an ancient tree emerge from the roof.
Space-distorting statue in exactly-square corner of corridor. Shaking right hand will increase number of corners until corridor is mile-long side of polygon. Shaking left hand will decrease it again.
Room F.
One of those Ripley's Believe It Or Not rooms where there's a row of mirrors along one wall and once you go around the corridor you can see through them. Couple of BRASS SATYRs behind mirrors making fun of PCs, will flee as they approach. If the PCs linger, SCABOXIS the EVIL HUNTER will come through on the other side of the mirrors and accidentally reveal something they would kill to keep secret.
Room G.
Bunch of BRASS SATYRs quivering in fear as you approach. SHIELD DRAGON followed you in, is directly behind you.
Room H.
SIEGE ORB's walk-in wardrobe. One entrance through wardrobe doors, one hidden behind layers of clothing. Careful searching will reveal a GLASS BELT, two living scarves that try to strangle you and a BRASS SATYR in fancy dress.
Room I.
SOUND: Burble of distant river.
Looks like empty room. Actually maw of cave leviathan, those weird stalagmites its teeth. Glimmer of treasure deep in gullet is pyrite lure. TOTEM RAYs pick dead flesh from between teeth.
Room J.
SMELL: Stagnant air and decay.
Lightless oubliette. MYRIVER the ARROGANT MERCHANT has been trapped in here for at least twenty years, some BRASS SATYRs coming by to feed and water them occasionally.