When submerged in water zombies turn invisible (not a potion effect). In the even that they are in 1 or 2 blocks of water the part of their body above water is still visible but the submerged part is not.
In the provided image you can see the tops of the zombies heads however the rest of the is invisible.
- duplicates
-
MC-197328 Entities sometimes don't render behind the water surface on Fast or Fancy graphics
- Resolved