The bug
When you're killing a mob, and try to hit even the mob is dying, you'll to hear the damage sound, even trough is dead.

How to reproduce the bug
1. Try to kill any mob (cow, creeper, enderman, etc...).
2. When the mob is dying, try to hit multiple times.
3. The mob will reproduce the sound of damage even trough is dying.
4. Also, try to do this bug when thin mob is in the lava, is more effective.

I published a video on Twitter for understand this bug There is the link:
https://twitter.com/ErickBrother22/status/914512069751447554