Varan the Unbelievable/YMMV

Awesome Music: Seriously, this is Akira Ifukube's most reused and referenced score, next to his work for King Kong vs. Godzilla in 1962.
- The Fierceness of Varan I and Fierceness of Varan II would both later be edited and modified to become Godzilla's theme in King Kong vs. Godzilla and Mothra vs. Godzilla. Another modified version of it can be heard as the Gotengo's theme in Atragon, specifically during the test run.
- Mystery of the Twentieth Century would later be used in Dogora as the music when the military is creating the synthetic wasp venom. Hell, this theme has been featured in some form in at least four more films:
  - Ghidorah, the Three-Headed Monster - Matsumoto City and King Ghidorah
  - The War of the Gargantuas - Wiring Complete
  - Destroy All Monsters - Remote Control Destruction
  - Space Amoeba - Launching of the Helios
- The first few seconds of the opening music would later be expanded and modified to become King Ghidorah's theme.
- Varan vs. Fighter-Bomber Neptune would be reused and modifed in Frankenstein vs. Baragon when the ship transporting Frankenstein's heart is traveling across the ocean and again in Battle in Outer Space as the Battle in Outer Space March.
- The first twenty or so seconds of Varan Lands at Haneda Airport would later be reused in Godzilla vs. King Ghidorah when Emmi pushes the Dorats out of the ship and onto Lagos island, as well various moments inside of the Futurian Mothership and outside when the military is setting up camp around the vessel.