What name did Game Freak originally use for the Pokémon project?

Game Freak originally called the Pokémon project Capsule Monsters.

The early concept grew from Satoshi Tajiri’s interest in collecting insects and from the Game Boy’s ability to connect two systems with a Link Cable. Tajiri imagined players collecting creatures and exchanging them with one another rather than simply competing.

The name Capsule Monsters reflected the idea that creatures could be stored in capsules. Because the phrase could not be trademarked, the project was later renamed Pocket Monsters, which became Pokémon in international branding.

The capsule concept remained visible in the finished games through Poké Balls, the devices used to catch and store Pokémon. The name is not the same as Pokémon’s Japanese title, Pocket Monsters, so the two stages of the project are easy to conflate.