The bug

Piglins, hoglins and zoglins will attempt to attack invulnerable mobs after the invulnerable mobs themselves attack them. But they do not attack, they'll just swarm the invulnerable mobs. No other mob does this.

How to reproduce

1. Use this command:

    /summon minecraft:snow_golem ~ ~ ~ {Invulnerable:1b} 

2. Spawn a piglin/hoglin/zoglin
   → They'll make their angry ambient sounds and runs towards the invulnerable snow golem not knowing that the golem is invulnerable.