|This article is written from the Real Life point of view|
Ing Battle is the theme that plays during a fight with the Ing in Metroid Prime 2: Echoes. It is also used for the Dark Alpha Splinter, Jump, Boost, Spider and Power Bomb Guardian battles, but does not necessarily play during every battle with one or more Ing. It also plays during cutscenes that involve the Ing in some manner, such as Samus's first encounter with them (where it is part of a medley), while viewing the final report of GFMC Task Force Herakles, and as Samus is escaping Dark Aether in the ending.
The theme can be heard here.