Minecraft wiki entry for Ravager, associated text: When blocked by a shield while attacking, no damage is dealt and knockback is halved. The ravager also has a 50% chance to become stunned and unable to move or attack for 2 seconds. After this period, it emits a roar by opening its bottom jaw and closing it and that deals 6 damage and a knockback of 5 blocks to nearby entities. The roar knocks back nearby illagers without damaging them and has no effect on other ravagers. Illagers that are knocked back by the ravager's roar can still take fall damage.