Once again it's time to check for facts. Rodan,Mothra & Varan were NOT Godzilla spin offs they had their own stand alone features before they appeared in a Godzilla film.
1. RODAN 1956
2. VARAN 1958 (started out as a U.S.A. T.V. pilot)
3. MOTHRA 1961
FIRST GODZILLA FILM
1.RODAN & MOTHRA... GHIDORAH the THREE HEADED MONSTER 1964
2.VARAN ...DISTROY ALL MONSTERS 1968 (ONLY A FLY-BY)
3.MOTHRA...MOTHRA VS GODZILLA (GODZILLA VS THE THING) 1964