Animals are a mobile food source. They must be killed before food can be harvested. Animals come in a variety, depending on map environment.
Gameplay[]
Animals exhibit a large range of behavior styles, from passively roaming the map to actively attacking a player's units. Once killed, however, they are all usable as food sources (excluding some special versions found in specific quests).
Unlike in other games in Age of Empires, animals can be killed by military units without consequence and the food quantity doesn't decay after an animal is killed. Conversely, herdable animals also don't fatten over time like in Age of Mythology and onward.
Celts can train their own unique animal, the Sacred Deer, both for their Sacrifice rituals or to use as further food sources (animals used for sacrifice can't be harvested for food). The Norse War Dog is classified as an huntable animal, but can't be used as a food source. Both of these are unique in that they don't take up population space like soldiers, but have their own build limits instead.