Mobs (in my case of discovery, passive mobs) seemingly disappearing when logging out and logging back into Minecraft. The invisible mobs still have a push effect, but the hit boxes are undetectable.
MC-138479
Ghosting Passive mobs
Resolved
Duplicate
0
Aidan A Wilson
(Unassigned)
Unconfirmed
Minecraft 18w43c
Retrieved
Can confirm for hostile mobs too. In one case the skeleton became visible again after relogging. In another case a spider and a zombie didn't after several relogs. No hitbox for either of them.