Monster Surprised You

Monster Surprised You is Disc 2, Track 2 on the Xenoblade2 Original Soundtrack. It plays during battles at the end of certain sidequests, as well as the following battles in Xenoblade Chronicles 2, and often (but not always) in the cutscenes immediately prior:
 * The Megalo Aligo on the Ancient Ship.
 * Dughall on the Titan Battleship.
 * Vandham in Uraya.
 * The Elder Arachno in Uraya.
 * Menacing Jo, Cartbreaker Grzeg, and Benjamin the Brain in Gormott.
 * Lila in Alba Cavanich.
 * Lila in the Abandoned Factory.
 * Aeshma's power lines in Temperantia.
 * Aeshma’s Core in Temperantia.
 * Addam's Phantasms in the Spirit Crucible Elpys.
 * The Deadfire Guldo in the Land of Morytha.
 * The Darkblood Guldos in the Land of Morytha.

It also plays in the following battles (and cutscenes prior) in Xenoblade Chronicles 2: Torna ~ The Golden Country:
 * Gort in Torigoth.
 * The Slithe Jagron in Aletta (for the first phase of the battle).