Drifters are undead hostile mobs that inflict Slowness.
In any location a Drowned would spawn below Y=46, a Sunken Drowned might spawn instead.
Sunken Drowneds can also be spawned via a Drowned Necromancer's attack, or from Ocean Monument Trial Spawners.
Sunken Drowneds will always spawn with a Trident, Iron Sword, or Iron Axe, all of which have a chance of dropping.
Guaranteed drops:
0-2 Rotten Flesh (amount boosted by Looting)
Rare drops (these drops aren't guaranteed, and the mob must be killed by a player or tamed Wolf):
1 Copper Ingot
1 Prismarine Crystals
1 Prismarine Shard
Rare drop chance is boosted by Looting.
Sunken Drowneds act like Drowneds, but are faster both on land and while swimming. Also note that they have more natural armor (8) compared to regular Drowneds (2).
Sunken Drowneds are affected by the Impaling and Smite enchantments.
Heeeeere's Drowned-y!
Health: 20
Natural Armor: 8
Type: Hostile Undead Aquatic Monster