Fish (mob)

"You're not the only new explorer of the updated oceans, mind. We've filled the seas with new types of fish! Above is the delightful pufferfish, which filled me with delightful poison because I was too busy taking that screenshot to swim away in time :("

- Tom Stone

Fish are common passive mobs found in oceans and rivers. They come in 4 main variants: cod, salmon, puffer fish, and tropical fish.

Spawning
Cod spawn in cold, regular, and lukewarm oceans.

Puffer fish and tropical fish spawn in lukewarm and warm oceans.

Salmon spawn in frozen and cold oceans, and unlike the other two variants, can also spawn in rivers.

Drops
Fish drop 1 of their item form when killed: raw cod, raw salmon, pufferfish or clownfish. The drop will never be cooked, even if the fish is killed while on fire. A tropical fish will drop clownfish no matter what its type, pattern or colors are.

Behavior
Cod, salmon and tropical fish tend to swim in schools of fish (a maximum of nine cod, nine of the same tropical fish or six salmon per school). Salmon are able to jump up waterfalls.

Defenses
None of the four types of fish are able to survive out of water. Outside of water, they will flop around for a while and eventually die of suffocation damage. When cod, tropical fish and salmon are outside of water, they will lay on their sides.

Puffer fish will puff up when approached by a player, going from unpuffed, then semi-puffed, to fully puffed. Puffer fish are technically passive mobs but going near one when fully puffed will inflict the player with seven seconds of, and touching them in their puffed form will deal some damage separate from the poison.

Fish are a part of the group of mobs affected by the Impaling enchantment, which also includes squids, guardians, and elder guardians.

Tropical fish patterns
Naturally-spawned tropical fish come in 2 shapes, 16 colors, 6 patterns, and 16 colors for the pattern. These result in 3072 possible combinations. With commands, the player can summon tropical fish without patterns, giving a further 32 possible combinations.

Fish bucket
A fish bucket is a water bucket filled with fish.

To fill a water bucket with fish, it on a fish. a fish bucket will release the fish and water inside it.

The four variants of fish buckets correspond to the four variants of fish mobs. For example, a water bucket with a cod fish in it is called a cod bucket.

Trivia

 * Despite its item form being named "Pufferfish", the bucket and spawn eggs refer to the respective mob as "Puffer Fish".
 * Puffer fish will poison the player even when on Peaceful difficulty