What was the early working title for the Pokémon video games before “Pocket Monsters”?

The early working title for the Pokémon video games was “Capsule Monsters.”

Satoshi Tajiri developed the concept after enjoying insect collecting as a child. He imagined a Game Boy adventure in which players could collect creatures and exchange them through the system’s Link Cable. The project’s early name reflected the idea of storing creatures inside capsules.

Trademark difficulties led to several changes, including the names CapuMon and KapuMon. The project eventually became Pocket Monsters, the Japanese name behind the shortened international brand Pokémon.

The final games were released in Japan as Pocket Monsters Red and Green in 1996. “Capsule Monsters” is therefore a development-era name, not an alternate title of a commercially released Pokémon game. The Poké Ball concept also has a separate stated inspiration in the fictional Capsule Monsters from Ultraseven.