Rapidly moving slime or honey blocks allows the player to interact with blocks behind it, and causes certain blocks to disappear.

By moving slime or honey blocks in the most recent snapshot, they seem to 'disappear' for a short amount of time, allowing interaction with the blocks behind, and causing certain blocks to become invisible. This is most evident when the blocks are moving rapidly. As far as I have tested, this bug causes the following blocks to become invisible:

• Water

• Portal blocks (Nether and End)

• Stained glass

• Stained glass panes

• Signs

• Banners

• Smoke particles

• Slime and Honey blocks

Likely more, but this is all that I tested.