Ultra Galaxy Legend Side Story: Ultraman Zero vs. Darklops Zero (ウルトラ銀河伝説外伝 ウルトラマンゼロVSダークロプスゼロ, Urutora Ginga Densetsu Gaiden Urutoraman Zero Bui Esu Dākuropusu Zero) is a Japanese direct-to-video two part series, serving as a sequel of 2009 Ultra Series movie Mega Monster Battle: Ultra Galaxy. The series was released separately, Cosmic Collision (衝突する宇宙, Shōtotsu Suru Uchū) in November 26 and Zero's Suicide Zone (ゼロの決死圏, Zero no Kesshiken) on December 22, 2010. It is also served as a prologue to Ultraman Zero: The Revenge of Belial, and simultaneously promoting the film's release.