What was the original working name for Pokémon during development?

The original working name for Pokémon was Capsule Monsters. Satoshi Tajiri and the Game Freak team used this concept while developing the idea of collecting creatures in capsules.

The capsule concept reflected several influences, including Japanese capsule toys and the monster capsules seen in the television series Ultraseven. Tajiri wanted players to catch creatures, store them, and exchange them with friends. The Game Boy's link cable made that exchange possible and became one of the project's defining features.

The name Capsule Monsters proved difficult to trademark, so the project was renamed Pocket Monsters. In Japanese, Pocket Monsters became Poketto Monsutā, later shortened in Roman letters to Pokémon. The accent in Pokémon distinguishes the franchise's name internationally. Because development lasted several years and the final name became so familiar, many fans never encounter the earlier working title.