Information provided by Agent 005.
CHIKYU BOEIGUN/EARTH SELF-DEFENSE FORCE (a.k.a. THE MYSTERIANS) 1957
The artillery that looks like satellites are the Markalite cannons from this
movie and were also used in its sequel UCHU DAISENSO/GREAT SPACE WAR (a.k.a.
BATTLE IN OUTER SPACE) 1959. The music used in that sequence is taken from
MYSTERIANS also.
SAN DAIKAIJU CHIKYU SAIDAI NO KESSEN/THREE GIANT MONSTERS GREAT BATTLE ON
EARTH (a.k.a GHIDRAH, THE THREE HEADED MONSTER) 1964
The fake title of the movie is an obvious parody of this movie and the others'
garish titles. King Orochi is King Ghidorah with just one eye on each head
instead of two, and the three people against the monster parodies the scenario
of the final battle. Kaede spoofs the Venusian (Martian in U.S.) priestess
who's a princess with amnesia and prophesies great dangers in the movie.
Momiji and Kaede in the fur-lined coats and talking in unison parodies the
infamous Shobijin, Mothra's priestesses, who also appear in MOTHRA VS.
GODZILLA (a.k.a. GODZILLA VS. THE THING) 1964. Music from KAIJU
DAISENSO/GREAT MONSTER WAR (a.k.a. GODZILLA VS. MONSTER ZERO) 1965 is also
used and is the 2nd movie to feature King Ghidorah.
GOJIRA/GODZILLA (a.k.a GODZILLA 1985) 1984
Kunakida emphasizing that nuclear weapons can't be used is most likely a
parody of the Japanese Prime Minister stating Japan's nuclear policies to the
Russian and American ambassadors from this movie.
KAITEI GUNKAN/UNDERSEA BATTLESHIP (a.k.a ATRAGON) 1963
The big submarine/rocket ship that rises from the sea is the Goten-Go (Atragon
in the US) from this movie. The music used in its scenes in this omake is the
theme music.
All these are Toho movies with music by Akira Ifukube, special effects by Eiji Tsuburaya, directed by Ishiro Honda, and produced by Tomoyuki Tanaka, the "Godzilla Forefathers" (they all worked on the original classic), with the exception of GODZILLA 1985 (with only producer Tanaka on board).