Kago appear in Super Metroid. Here, the Kago will only attack Samus if she threatens their nest by attempting to destroy it and will ignore her if she does not. These creatures are small insects that resemble the bugs in Metroid: Zero Mission
In Metroid Fusion, the X mimic Kago nests. In Fusion, they are able to absorb an extra X to grow into a column of mass that can damage Samus. In this form, it can be frozen, or can be killed with the Speed Booster or a Power Bomb. Kago nests are scattered throughout Sectors 2, 4, and 5, able to be frozen and used as large platforms or sometimes blocking Samus's path.
A Kago nest mimicked by an X