Squid

Squid are 8-armed mobs that spawn in water. Squid are always passive towards the player, akin to the other passive mobs found on land. They can be found in water of any depth, in any biome, and spawn on any difficulty.

Appearance
Squid have 8 tentacles, blueish-teal skin and teeth that can be found underneath the head. They have two eyes which appear wall-eyed. Despite being called squid in-game, their body arrangement is closer to that of a real-world octopus.

Uses
When killed, each squid will drop 1 - 3 ink sacs that can be used to dye wool. The ink sac, like a unit of dye, can be applied directly to sheep before shearing to make black wool or mixed with varying proportions of bone meal beforehand to yield light gray and dark gray dyes. It is also possible to craft a book and quill using an ink sac, a feather, and a book.

Behavior
When moving about, the squid's tentacles open and close, giving them an appearance of pushing themselves forward. Squid will hover in place and wander around one layer aimlessly and do not deliberately interact with the player, except if attacked. It will try to swim away from the player.

Squid are prone to gather near light under water, such as a Redstone lamp, glowstone or Jack-O-Lanterns.

Squid could stay alive but become immobile when beached on the land until before 1.4.4pre. From that version they suffocate in air. They can take fall damage and burn like any land mob, but, due to being aquatic they cannot drown.

Squid (unlike land-based mobs) can swim against a current and not get pushed by it.

Farming
Squid, although able to swim against the current, can not swim up a waterfall. The simplest way to trap large numbers of squid is to dig an approximately 8x8 hole three blocks deep at the bottom of an ocean or large lake. The fall of water into the hole will trap squid that wander over it. Complicated funnel and channel systems can bring squid from multiple traps to a central location for the player to kill. Here is a tutorial to a squid farm

Trivia

 * Squid are the first and so far the only water mob.
 * Hitting a squid underwater causes them to rise approximately 1/3 to 1/2 a block.
 * Squid cannot be damaged by attacking their tentacles.
 * Squid behave like some land mobs and attempt to ride a Minecart. However this is not always useful as rails and water cannot occupy the same block.
 * Squid are the first passive mob that spawn at any light level, in water, and without grass.
 * When the world is loaded, all squid are aligned with the tentacles facing east.
 * In RC2, when Squid came out of the water and were hurt, they made the new player hurt sounds.
 * Squid spawners will only spawn them on layer 60, as the large water bodies (such as oceans, rivers and ground lakes) appear only on that depth. This means squid can no longer spawn in mountain springs or underground lakes.
 * Squid and Bats are the only passive animal that cannot breed; due to this, however, they will spawn like the other animals used to.
 * It is possible for a squid to receive fall damage.
 * Squid, along with Ocelots and Bats are the only passive mobs that can despawn.
 * It is possible for squid to spawn in the fountains of Strongholds, underground lakes, wells, obsidian patches, cobblestone generators, and caves with water running through it.
 * Squids are EVIL!

Gallery
Calamar Tintenfisch Pieuvre Tintahal Inktvis Kałamarnica Спрут 鱿鱼