Suggestions by @zenith2024

Biollante

as Biollante in Godzilla: Afterlife

Megalon

as Megalon in Godzilla: Afterlife

Jesse Lee Soffer

as Zone Fighter in Godzilla: Afterlife

Zone Fighter

as Zone Fighter in Godzilla: Afterlife

Obsidius

as Obsidius in Godzilla: Afterlife

Desghidorah

as Post Credits in Godzilla: Afterlife

Gigan Rex

as Post Credits in Godzilla: Afterlife

Viras

as Post Credits in Godzilla: Afterlife

Mechagodzilla (GODZILLA anime trilogy)

as Post Credits in Godzilla: Afterlife

Iris

as Post Credits in Godzilla: Afterlife

Spoiler

as Post Credits in Godzilla: Afterlife

Krystalak

as Krystalak in Godzilla: Afterlife

Godzilla Junior

as Godzilla Jr in Godzilla: Afterlife

SpaceGodzilla

as SpaceGodzilla in Godzilla: Afterlife

Rodan (MonsterVerse)

as Rodan in Destroy All Monsters: Annihilation

Minilla

as Hercules in Destroy All Monsters: Annihilation

Jet Jaguar

as Jet Jaguar in Destroy All Monsters: Annihilation

Godzilly (Gojirin)

as Gojirin in Destroy All Monsters: Annihilation

Spoiler

as Post Credits in Destroy All Monsters: Annihilation

Monster X

as Post Credits in Destroy All Monsters: Annihilation