What was Pokémon called during its early development before the name Pocket Monsters was chosen?

During early development, Pokémon was called Capsule Monsters.

Satoshi Tajiri’s initial concept focused on collecting creatures and exchanging them between Game Boys through the Link Cable. The working title Capsule Monsters reflected the idea that creatures could be stored in small capsules, later represented in the finished series by Poké Balls.

The name proved difficult to trademark, so the project was renamed Pocket Monsters. In Japan, that title became Poketto Monsutā, while the internationally familiar shortened form Pokémon was eventually used for the franchise. The change was part of the long development process rather than a storyline event.

The capsule idea also connected with Japanese monster media that influenced the project’s design. Tajiri wanted players to capture, carry, trade, and release creatures in a way that felt different from simply fighting enemies. Remembering Capsule Monsters helps explain why Poké Balls and creature collection became such central parts of Pokémon’s identity.