Squid

Squids are the first water mobs in Minecraft. They are 8-armed passive mobs introduced in the Beta 1.2 update. Squids are found in water of any depth in any location, and drop ink sacks when killed. They spawn on any difficulty and do not attack, akin to the other passive mobs found on land.

Behavior
When moving about, the squid's arms open and close making it seem like they are pushing themselves forward. Squids swim around aimlessly. They are unable to swim upwards so they generally sink to the bottom of the water moments after they spawn.

When forced onto land, squids become immobile and will eventually suffocate to death. They take fall damage and burn like any land mob.

Drops

 * 1-3 ink sacks

Trivia

 * It is impossible to pull a squid onto land with a fishing rod.
 * Hitting a squid underwater causes them to rise approximately 1/3 to 1/2 a block.
 * Due to a bug in beta 1.2, squids can end up above water, swimming through the air (This can be done by removing the water around them with a bucket. However it occurs naturally as well).
 * Squids cannot be damaged by attacking their tentacles, unlike Ghasts.
 * Squids will spawn in The Nether if the necessary spawning conditions are met (using an inventory hack).

Tintenfisch