Guardian is a hostile aquatic mob that spawns in and around ocean monuments. It attacks using a slow-charging laser beam and inflicts retaliatory damage when hit by melee attacks due to its spiked defenses. Guardians serve as protectors of ocean monuments, making them a challenge for players exploring these structures.

Guardians drop 0–2 prismarine shards upon death and have a 2.5%–5.5% chance to drop 1 random fish. They also drop 10 experience when killed by a player. Guardians cannot be bred and only spawn naturally inside and around ocean monuments. Unlike Elder Guardians, they respawn infinitely as long as the monument remains intact.

Guardians are hostile mobs and attack players, squid, and axolotls on sight. Their laser attack locks onto a target, dealing increasing damage over time unless the beam is interrupted by obstacles. When attacked in melee combat, their spines extend, dealing retaliatory damage to attackers. Guardians swim erratically, making them difficult to hit, and they are immune to drowning and fall damage. They are commonly farmed for prismarine shards and fish drops, making them essential for obtaining sea lanterns and prismarine blocks.