There has been a rumor that in the Japanese version of "Godzilla vs Gigan" rather than hearing Godzilla and Anguirus talk, we see speech bubbles pop out of their mouths.
I can confirm this rumor to be true. This video clip was taken direct from the DVD, which apparently contains both the English dubbing AND the Japanese visuals.
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Finally, something we agree on! But, yeah, Godzilla has taken out creatures twice his size, and...