What was Pokémon called during its earliest development before the name Pokémon was adopted?

Pokémon was originally called Capsule Monsters during its earliest development.

Game Freak creator Satoshi Tajiri proposed a game based on collecting and exchanging creatures. The initial concept used the name Capsule Monsters, inspired by the idea of creatures being stored in small capsules. Trademark problems made that title difficult to use, so the name passed through intermediate forms including CapuMon and KapuMon.

The project eventually became Pocket Monsters in Japan, shortened internationally to Pokémon. The final name combined “pocket” and “monster” and fit the series’ central idea: carrying creatures in compact Poké Balls. The original Japanese games were titled Pocket Monsters Red and Green when they launched in 1996.

A common mix-up is assuming Pokémon began with its final English branding. In fact, the development history predates the public release and includes several working titles. The name change happened before the franchise became known worldwide.