Ritchie

"Go Sparky!"

- Ritchie in the anime

Ritchie is a friend of Ash Ketchum and one of his oldest rivals.

Season 1: Indigo League
He teamed up with Ash to get the Pokémon back which were stolen. He was then forced to battle Ash in the Indigo League and defeated him, as Ash's Charizard wouldn't obey him. He battled Assunta for the next round, but lost. He went to Ash to have few words about their loss and defeated Team Rocket, who wanted to take their Pikachu away.

Season 2: Adventures on the Orange Islands
Ritchie appeared in the opening scene of Adventures on the Orange Islands season, but he did not appear in any of the episodes.

Season 5: Master Quest
Once in Johto he helped Ash save a baby Lugia and its mother from the clutches of the notorious Team Rocket.

Season EX: Chronicles
He was present in Pokémon Chronicles and has not been seen since.

Trivia

 * In Pokémon Diamond and Pearl, during the contests, there is a contestant named Luis. He seems to be based on Ritchie because of his outfit and having a Pikachu nicknamed Sparky.
 * Ritchie mentioned in Oaknapped! that he and Ash tend to catch the same Pokémon.
 * Ritchie's design is similar to Red from Generation I, he is a pallette anime swap for Red, the different Red clothes are Red & White Jacket, Shoes, and Hat, while having blue pants, Ritchie has Blue & Yellow Hat, Green Jacket, Pants, possibly Blue, Green, or Purple Shoes, the point this that he wear the outfit as Red do in Generation I not Generation III on Generation I.
 * In Friends to the End, Ritchie battled Assunta, but it was not specified whose Tentacool and Spearow were.