The Urchin is an aquatic mob that spawns in the oceans of the Overworld. They are one of the slowest of all mobs, moving at 1/32nd of a block (1/2 a pixel) per second. If hit or walked on, they will deal 3 damage and inflict poison for 18 seconds. They do not drop any items on death. Sneaking while walking on the same block as an urchin will prevent the player from taking damage from it.
Urchins can be picked up in a bucket, similar to fish, and they can be bred using kelp. Additionally, urchins' venom can be extracted using an empty bottle to get a potion of poison.
They are one of the few aquatic mobs that Axolotls will not attack.
Urchins only spawn at night, being one of the few non-hostile mobs to do so. They spawn in several ocean and beach variant biomes, including the standard ocean and beach, deep ocean, lukewarm ocean, warm ocean, and Black Beach. They also spawn in the White Sand Island.