Secrets - Pokemon Red, Blue and Yellow Guide - IGN

While there aren't any hidden codes in the game, there are a couple of secrets and odd glitches. Below, we list the most important ones. This page also

Grimer - Pokemon Red, Blue and Yellow Guide - IGN

Ponyta - Pokemon Red, Blue and Yellow Guide - IGN

Gloom - Pokemon Red, Blue and Yellow Guide - IGN

Vaporeon - Pokemon Red, Blue and Yellow Guide - IGN

Raichu - Pokemon Red, Blue and Yellow Guide - IGN

Gengar - Pokemon Red, Blue and Yellow Guide - IGN

Jolteon - Pokemon Red, Blue and Yellow Guide - IGN

Abra - Pokemon Red, Blue and Yellow Guide - IGN

Secrets - Pokemon Red, Blue and Yellow Guide - IGN

Nidoran - M - Pokemon Red, Blue and Yellow Guide - IGN

Hitmonchan - Pokemon Red, Blue and Yellow Guide - IGN

Exeggutor - Pokemon Red, Blue and Yellow Guide - IGN

Gyarados - Pokemon Red, Blue and Yellow Guide - IGN