In Java Edition, only aquatic mobs receive the extra damage. Aquatic mobs include dolphins, guardians, elder guardians, squids, turtles and all variants of fish, but not drowned because drowned are classified as undead mobs rather than underwater mobs.
In Bedrock Edition, the damage applies to other players, as well as all mobs when in contact with water: underwater, in flowing water, and in rain.
|1.13||18w07a||Along with the addition of tridents, the Impaling enchantment has now been added.|
|Upcoming Java Edition|
|Combat Tests||Combat Test 4||Impaling now deals extra damage to all mobs in water or rain.|
|1.4.0||beta 22.214.171.124||Added the Impaling enchantment as part of Experimental Gameplay, which is able to be applied to the new tridents.|
|beta 126.96.36.199||The Impaling enchantment has now been fully implemented.|
|Legacy Console Edition|
|TU69||1.76||Patch 38||Along with the addition of tridents, the Impaling enchantment can now be applied to them.|