Gaia

Gaia is a non-playable team on Age of Empires and Age of Empires II, to which all the natural environment units you find around the map belong. The Age of Mythology equivalent to Gaia is Mother Nature.

Human Units
If a human unit, sheep or horse is placed under GAIA's control in Create Scenario, it will become the possession of a human player's team should one of his/her units come across it. This is a common method used in campaigns, and can sometimes be used to place secret units on a map, obtainable through exploration.

Nature & Environment Units
All nature and environment units belong to GAIA. Below is a list of commonly found ones:

Animals

 * 1) Deer
 * 2) Dire Wolf
 * 3) Elephant
 * 4) Fish
 * 5) Gazelle
 * 6) Hawk
 * 7) Jaguar
 * 8) Javelina
 * 9) Lion
 * 10) Macaw
 * 11) Whale
 * 12) Wild Boar
 * 13) Wolf

Miscellaneous

 * 1) Destroyed Building
 * 2) Flowerbed
 * 3) Flowers
 * 4) Grave
 * 5) Haystack
 * 6) Head
 * 7) Nine Bands
 * 8) Roman Ruins
 * 9) Rocks
 * 10) Sea Rocks
 * 11) Sign
 * 12) Statue