Dolphin

"Social creatures of habit, dolphins can be found swimming together through the ocean in large groups. As they spot the player, they will try to interact with them, showing them just how highly intelligent and curious they are. Above all else – they are extremely playful!"

- Per Landin

Dolphins are neutral mobs that live in the ocean (but not the frozen one).

Spawning
Dolphins are found in large groups in all ocean biomes, except frozen oceans.

Drops
When killed, dolphins drop 0–1 raw cod, with the chance of an additional fish per level of looting.

Behavior
Dolphins will normally swim in groups, occasionally leaping out of the water to get air, they're also able to jump from one body of water to another. They will also try to chase after players in boats. They are also able to ride in boats themselves and can thus be transported.

Players who swim near dolphins will receive Dolphin's Grace for 5 seconds. On the Bedrock Edition, the player simply gets a speed boost without a status effect.

Dolphins are lured by dropped items, knocking them around and chasing them. If the player or other mob hits a dolphin, the entire group will become hostile (like wolves and zombie pigmen) and hit the player back.

Feeding dolphins raw cod will improve their "trust" with you, depending on the amount of fish fed, causing them to interact with the player more.

When dolphins are fed raw cod, they will swim to the nearest shipwreck or underwater ruins. Because they are locating the chest in the structures rather than the structures themselves, breaking the chests will cause the dolphin to locate a new structure with intact chests.

Dolphins also avoid guardians and elder guardians.

Weaknesses
If a dolphin is not in water, it will start taking suffocation damage after a while (about two minutes), and eventually die, similar to squids. This also applies if a dolphin rides in a boat. Dolphins cannot ride boats on the Bedrock version, similarly to squid, turtles, and all types of fish. When on land they will actively seek out a body of water. They will also start suffocating immediately after entering the nether.

They can't survive without getting air every once in a while either, so if they stay submerged for about 4 minutes, they will begin drowning. The water breathing effect does not prevent them from drowning.

Because the dolphin is an aquatic mob, they are affected by impaling enchantment.

Data values
Dolphins have entity data associated with them that contain various properties of the mob. Their entity ID is.

Trivia

 * To create the sounds that the dolphins make in the game, Mojang's lead sound designer, Samuel Åberg, went to Kolmården Wildlife Park to record real dolphins.
 * If a dolphin is beached on land and in a hostile state, it will move slowly towards its target.