When killed by a mob multiple times all mobs of that type will turn invisible, this will only happen when there are alot of command block running (of a 20Hz clock) Cannot recreate in world without the command block clocks
Linked issues
Comments 5
More like MC-68403 since it involves dying and respawning.
... but the mobs die and respawn. MC-68403 is about player dying and respawning...
When killed by a mob multiple times
This seems to be talking about players being killed by mobs (unless I'm missing something here); also I don't think mobs can respawn in Vanilla Minecraft xD.
Dupe of MC-65040