What was the Pokémon franchise originally called during early development?

During early development, the Pokémon franchise was originally called Capsule Monsters.

Satoshi Tajiri's first concept centered on collecting creatures that could be stored in small capsules and exchanged between Game Boy players. The capsule idea also reflected Tajiri's interest in Japanese monster television, including shows in which giant creatures emerged from compact containers.

The name Capsule Monsters proved difficult to trademark. The project was then renamed Pocket Monsters, which became the Japanese title Poketto Monsutā. The shortened form Pokémon later became the internationally recognized brand name.

This history explains why Poké Balls are such a central part of the franchise. The final name emphasizes pocket-sized creatures rather than the exact early development concept. Capsule Monsters was a working title, not a released game or a separate Pokémon generation.