Silver

As a child, he was kidnapped and raised by the evil Masked Man, where he met and became close with Blue. Together they escaped, and Silver went to Johto, where he later stole Professor Elm’s Totodile. This is similar to the way Blue stole Professor Oak’s Squirtle upon her return. Silver’s special skill, as described by Professor Oak, is Pokémon trading (taught to him when he was with the Masked Man), and he is known as the “Exchanger” (換える者). As revealed in the FireRed & LeafGreen chapter, Silver is the son of Team Rocket boss Giovanni. As a young child, Silver was kidnapped by the Masked Man to serve under him. It was there that he met and befriended Blue, and together they escaped from the Masked Man and parted ways, but not before Silver gave Blue his Horsea and received her Snubbull.