Chicken

Chickens are passive mobs that first appeared in Alpha mode. The main purpose of chickens is to supply feathers, Raw Chicken and eggs, essential for arrows, food and cakes, respectively. Chickens are 0.875 blocks tall, 0.5 blocks wide and 0.8125 blocks long.

Behavior
Chickens appear to wander around aimlessly, but actually and subtly possess decent pathfinding ability. They will make no attempt to stay out of water, and a common sight is several chickens bouncing up and down in the water. They appear to be drawn to caves, since they move more easily down ledges than up them. Chickens are also drawn to light in a dark environment and will swim upstream to get to it. Chickens will also climb simple steps, but not a ladder, to escape a pit. Since the Beta update they seem to be the most common mob. Chickens often spawn alone, but can spawn in groups of 2-6. Like all other passive mobs, they seemingly move randomly in a natural environment. Chickens seem to make attempts at escaping (if trapped/fenced) by constantly jumping into doors or fence gates if available.

Chickens lay eggs which can be thrown at enemies or used as an ingredient in cakes. Chickens lay an egg on average about every 7 minutes (it took 40 minutes for 9 chickens to lay 50 eggs = 7.2 minutes/egg). Since the Beta 1.0 update, Chickens have a 1/8 chance of being spawned from a thrown egg.

Trivia

 * Chickens are the second smallest mob (the first being small slimes, the third being Cave Spiders). They are able to fit through 1x1 gaps.
 * They take no fall damage, and when they fall they make a flapping animation and fall slower than normal.
 * When a chicken is killed, and if it has a boost from the hit or is thrown over a cliff by the hit, the "corpse" will also fall more slowly than normal, and the wings will still make a flapping animation.
 * When a chicken is riding a minecart, it is impossible to attack the chicken rather than the cart as it is completely inside the shape of the cart.
 * Raw Chicken was introduced in Beta 1.8. Before this, chickens only dropped feathers on death.
 * Cooked Chicken can easily be obtained by letting chickens fall onto a block of burning netherrack from which they can run off.
 * In 1.8 Chickens seem to drop Eggs more often than usual, but this is only because animals are, since then, persistent.
 * In 1.8, Chickens need a large area to walk around in or they will start dying on their own. This happens because the chickens push each other into the walls, suffocating for a split-second. To solve the problem, make sure they are surrounded by fences and not solid blocks.
 * You can spawn chickens in the Nether with Eggs
 * It takes one full minecraft day or 20 minutes for baby chicks to become fully mature chickens.
 * Chickens are the only Overworld mob (bar the use of hacks/inventory editors) that can be bred in the Nether, by building a suitable area and throwing Eggs inside of it.

Appearance
Chickens are sometimes mistaken for ducks due to their wide beaks and ability to swim.