Venus

Venus is one of the four inner planets of the Solar System. It is a planet which is known for its extremely hostile environment and proximity to the Sun. Venus first appears in the 1964 film, Ghidorah, the Three-Headed Monster.

Ghidorah, the Three-Headed Monster
At some point before the events of the film, Venus was home to a vast and heavily-developed ecosystem, complete with a race of its own, the Venusians. King Ghidorah appeared from space and attacked the planet, eventually wiping out all life on the planet. Several years later, the spirit of one of the fallen Venusians possessed the Princess of Selgina, and convinced her that she was the last surviving individual from the spirit's civilisation's cataclysm. Selina then began to prophetically warn the people on Earth of Ghidorah's imminent arrival.

Trivia

 * In the American dub for Ghidorah, the Three-Headed Monster, all references to Venus are changed to refer to Mars instead.