Catch 'em, catch 'em, gotta catch 'em all! Gotta catch 'em all, CapuMon?! Here's a little bit of proto-Pokemon for the fans.
Initially, "Pokémon" creator Satoshi Tajiri intended to call his project "Capsule Monsters" after having been inspired by gashapon vending machines. While ultimately unable to secure the name "Capsule Monsters," Tajiri shortened it to "CapuMon" before finally settling on "Pocket Monsters." Also of note here are early designs for Gengar and what is presumably Nidorino.
Via: bulbapedia.bulbagarden.net
Early in-game animation sketches of catching a Pokémon.
Source: fuckyeahbetapokemonart
At first, one half of the Poké Ball would slide into the other instead of opening on a hinge as they do now. In addition, the button to open it appeared on the top.
Source: bulbapedia.bulbagarden.net
An early concept for an individual Pokémon's status page complete with what could possibly be a prototype Charizard.
Source: tikisaurus.com