Regarding your Gatling Gigan edit: we typically don't count appearances in episodes' recaps, title cards/intros, or next-episode previews. The only exception I can recall is the Godzilla Singular Point credits, which feature a ton of characters/monsters who aren't in the show proper at all.
EDIT: Whoops, I got ahead of myself and didn't see that Les already said similar. Hopefully this adds a little extra context.
