Theme: A room with a large blood pool, rising on the other side is a sheer cliff that drips with the same blood feeding the pool. The cliff is climbable but treacherous, handholds are slick, and the surface oozes with blood, as if bleeding. At the top is the exit.

Puzzle: Climb the wall but the moment they reach halfway or make too much of a disturbance (e.g. hammering in pitons, loosing rocks etc), a creature emerges from the pool below.

Climb fast or try and slow the creature.

Cliff height:

DC 15 Athletics to climb normally.

DC 18 if climbing fast (double movement).

DC 12 if climbing slowly and carefully (half movement, no noise).

Disturbance:

Loud spells (e.g. Thunderwave, Shatter)

Failed climbing checks (falling rocks, splashes)

Reaching XXft. height

Creature:

Kruthik Hive Lord - Make Devilish - will scurry up the wall before burrowing in and bursting out underneath a creature throwing them back down into the blood pool

Blood pool is a Giant Blood Ooze -

3d10+10 necrotic damage as the ooze absorbs blood

Engulf: Dex ST DC 18

Failure: 6d6 Acid damage, and the target is engulfed.

An engulfed target is suffocating, can't cast spells with a Verbal component, has the Restrained condition, and takes 6d6 Acid damage at the start of each of the oozes turns.

An engulfed target can try to escape by taking an action to make a DC 18 Strength (Athletics) check.

On a successful check, the target can move their swim speed through the blood pool.

Success: Half damage, and the target can move their swim speed through the blood pool.