Zombie

Zombies are hostile mobs, and the first of the kind implemented in Minecraft Pocket Edition. They drop 0-2 Feathers, 0-1 Carrots, 0-1 Potatoes, and 0-2 Rotten Flesh if they are killed, and usually spawn in groups of six. They also burn in sunlight, taking fire damage every second. Zombies can wear Armour in 0.12.1, which may or may not be enchanted. Zombies can also hold weapons and items they come upon.

Offense
Zombies attack the player by hitting them with their arms, while swinging them up slightly in the process. If they are on fire, they can also set the player on fire if they attack them, however running away will extinguish the fire.

Zombies have a small chance of spawning more zombies in a small radius when attacked by an entity.

Combat
Zombies are easy to kill with a sword, preferably stone or above. A Bow can also be used when fighting large groups of zombies.

Baby Zombies
Baby Zombies are variants of Zombies that have a 5% chance to spawn in place of any regular zombie. They run faster than the player, and do not burn in sunlight.

Baby Zombies have a chance of spawning on Chickens as a Chicken Jockey.

After Update 0.12.0 baby zombies have a chance to appear with armor or a tool which makes them harder to fight.

Trivia

 * After fire was removed in 0.3.0 due to bugs, they emitted smoke and received damage until they died. Since fire was added back, however, both Skeletons and Zombies burn in daylight.
 * There is a variant of Zombies known as Zombie Villagers that will be added in Update 0.12.0.
 * Zombies will not burn if in shade or water.
 * Zombies have the same face as the player's default skin, except painted green and black.
 * Zombies do more damage when they have low health.
 * In MCPE Lite, Zombies are presently the only hostile mobs.
 * If a zombie sees a villager, it will run forward to attack, but mostly, villagers run away long before zombies see them
 * If the Zombie is able to kill the Villager, it will turn into a Zombie Villager if the difficulty is set to Normal or Hard.
 * When the player kills a zombie wearing armor or holding an item, it may drop the armor or item. The same is true for Zombie Pigmen, Skeletons and sometimes Wither Skeletons
 * If a zombie wears a helmet it will not burn in the sunlight. This will happen to skeletons too
 * Zombies cannot see you through glass.
 * Zombies can see holes and drops and will not walk into them, unlike creepers.