Cow

A Cow is a common animal that can be found just about anywhere in the overworld.

Natural generation
Cows can spawn in small herds on grass blocks with a high enough light level.

Shearing
Shearing a mooshroom or moobloom will turn it into a cow.

Milking
A cow can be milked by right clicking it with a bucket.

Drops
Cows will drop 1 - 5 leather upon death.