Deer live in the forests and are nourished only by plants. They are absolutely peaceable and very shy. They provide a wealthy source of food, but you must be very quick or work in teams in order to hunt them down. Bows are effective weapons for that task.
Note that if summoned, the deer can attack other players on PvP worlds. Found in many places, they drop meat and ham.
Damage Taken From Elements
Deer are usually not offensive creatures. A deer will retreat at 25 (100%, full) health.
Attack them using "chase opponent", as it can be rather difficult to catch these four legged creatures.