Acquire a map from a cartographer villager, then enter the revealed structure. [Bedrock Only]

Ring the bell with a hostile enemy in the village.

Visit all Ocean Biomes.

Craft a Banner using an Enchanted Apple.

Find an underwater ruin.

Receive a gift in the morning from a tamed Cat.

Collect any fish in a bucket.

Eat nothing but Kelp for 3 days.

Use a Dried Kelp block as fuel in a furnace.

Using the Frost Walker boots, walk on at least 1 block on frozen water on a deep ocean.

Dye your bed a different color.

Throw diamonds at another player.