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. Tropical fish have a further 3072 possible combinations of shape, color and patterns.

Spawning
Cod spawn in regular, cold, 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 their item form when killed. For example, when a cod is killed, it will drop one raw cod. In the case of cod and salmon, the drop will always be raw, even if the fish is killed while on fire. Tropical fish drop Clownfish when killed.

Behavior
All four types of fish are not able to survive out of water. If 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.

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

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.

Tropical fish populate Lukewarm and Warm Oceans. They come in many different colours and patterns, and will drop Clownfish when killed.

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

 * Fish were also jokingly teased in the fake snapshot 12marc40awesome, along with coral and "fish blocks".
 * Despite its item form being named "Pufferfish", the bucket and spawn eggs refer to the respective mob as "Puffer fish", which is likely wrong.
 * Salmon tend to swim in groups of six or less.
 * Tropical fish swim in schools of up to nine fish, which contain the same type of tropical fish.