Mooshroom

Mooshrooms are cow-like mobs that spawn in the Mushroom Biome (although there have been instances of them spawning in other biomes as well), covered with red mushroom growths. They have 2 mushrooms on their body and one on their head.

Uses
Mooshrooms can be sheared for 2-5 red mushrooms, which turns them back into normal cows. If killed, they drop leather and raw beef like normal cows do. Mooshrooms can be milked with a bucket like a normal cow, and can be "milked" with an empty bowl to obtain a refill of Mushroom Stew.

When players see a mooshroom for the first time the primary reaction is bda out

Behavior
Mooshrooms roam the Overworld Mushroom biome and occasionally other biomes in herds of 4—8. Mooshrooms make no attempt to stay out of water, and will bob up and down to stay afloat.

Breeding
All passive mobs (Excluding squid and villagers) can be bred using Wheat. Breeding a mooshroom with another mooshroom makes a baby mooshroom, while breeding a regular cow with a mooshroom makes a regular cow.

History
Mooshrooms were added in Minecraft 1.0 and were introduced in the Beta 1.9 Pre-release update. When first introduced, Mooshrooms solely inhabited the Mushroom biome, but as of Beta 1.9pre4 may spawn in other biomes as well.

Bugs

 * On SMP when a Mooshroom is sheared, a server-side cow spawns, as well as a client-side cow that spawns for the player who sheared the Mooshroom.
 * In Beta 1.9 pre 3, shearing a baby mooshroom will automatically turn it into a full-grown cow, along with giving red mushrooms (even though baby mooshrooms don't have any mushrooms on their bodies).
 * As of 1.9 pre 5, in SMP when a baby mooshroom is sheared, it turns into two normal cows and the two parent mooshrooms stop following them.
 * When a Mooshroom is sheared after it has already bred once, it can be bred again.
 * Possibly a bug: In addition to spawning in their natural Mushroom habitat, Mooshrooms may spawn in non-mushroom biomes as well.
 * In 1.0.0 SMP, right clicking on a Mooshroom with more than one bowl equipped will turn the whole stack into just one bowl of Mushroom Stew. (Untested in SSP)

Trivia

 * Mooshrooms are similar to infected insects with Cordyceps fungi. Just like Cordyceps fungi growing on infected insects and terrestrial arthropods, mushrooms also grow on the Mooshroom.
 * The Mooshroom's name is a portmanteau of "moo," the sound Cows make, and "mushroom."
 * In the Beta 1.9 Pre-release mobs folder in the minecraft.jar, Mooshroom's are referred to as redcows, most likely because their texture is mainly a red color shift of the cow texture. Also, Mooshrooms are referred to as mushroomcows as its entity ID.
 * When a Mooshroom transforms into a normal Cow by shearing, it creates a visual effect similar to TNT explosions.
 * There are only red mushrooms on mooshrooms, not brown ones.
 * If you breed a mooshroom with a normal cow, either a normal baby cow will be born or a baby mooshroom will be born.
 * Mooshrooms are the most resourceful mob in Minecraft: Mooshrooms can be "milked" with a bowl for mushroom stew; shearing them drops 2-5 red mushrooms, which changes them back into a normal cow that can be milked with a bucket; the Milk is used for making cake; and when you kill the cow it can drop 1-3 pieces of raw beef and 0-2 pieces of leather. This is a total of at least 7 items that can be directly or indirectly obtained from Mooshrooms/Cows.