Red is a character who surely needs no introduction to Pokémon fans. Red was a character from the very first Game Boy entries, and has become something of an icon for veteran players.
Red appears in Pokémon: Let's Go, but is only found in one location: Indigo Plateau.
Don't expect Red to simply appear, though - he will only battle the most worthy trainers. You'll need to have beaten at least 6 Master Trainers.
When you've done this, Red will appear outside the Pokémon League in the Indigo Plateau. His team is made up of level 85 monsters, and consists of Pikachu, Machamp, Arcanine, Lapras, Snorlax and Venusaur.
if you defeat Red, you'll earn the title Battle Master.