"Galactica Crunch" is an energy-based attack performed by Sailor Iron Mouse in the manga, crystal, and musicals.
Manga[]
Sailor Iron Mouse uses the attack in Act 50 against the Sailor Senshi, but it is countered by Space Turbulence and Submarine Violin Tide.
Musicals[]
In the musicals, the attack was first used in "Pretty Soldier Sailor Moon ~ Starlights - Legend of the Shooting Stars". Iron Mouse attempted to use it against Ami, but Saitou Izou got in the way and was knocked down instead.