22w14a, 22w15a, 22w16b, 22w18a, 1.19 Pre-release 3
If the player (or probably any other entity) is standing on top of a mud block as soon as that mud block becomes clay via the dripstone mechanic, the player will fall into the clay block. If there are no blocks around that clay block, this can additionally cause them to be pushed out of it sideways.
- Place mud
- Place a block below the mud
- Place a stalactite below the block
- Stand on the mud
- Wait or set randomTickSpeed to a high value
As the mud converts to clay, the player would be moved upwards slightly to accommodate the clay block's hitbox, as is done for farmland that becomes dirt.
The player is not moved upwards and falls into the clay as a result.