KOTS

Hitting/killing a monster leaves a pool with fluid corresponding to their "race". If the monster has a race that does not have a corresponding fluid, no pool is created.
Hitting a monster leaves item 2889 on same tile. Killing a monster leaves item 2886.
Each field decays to next state after some time (fluid field should be preserved when item is transpormed into next decay state).
There can be up to one after-hit pool and one after-death pool. Pools in next decay states are still considered pools.
When creating an after-hit pool, remove existing after-hit pool if it exists on that tile. When creating after-death pool, also remove existing after-death pool.