>>27991658James Turner actually works for Game Freak and is one of the main experts on 3D modelling there. He was also the mastermind behind Harmoknight.
Hitoshi Ariga is a mangaka who for Pokemon has drawn TCG art in the past. Outside of Pokemon, he's done some Mega Man stuff in the past to my knowledge
There's Atsuko Nishida, who actually designed most of the iconic Gen 1 Pokemon like the Pikachu, Charizard, and Eevee lines, and some assorted others throughout the years like the Zoroark and Cinccino lines in Gen V. Eventually she founded her own character design company, which designed characters for several games and a prefecture mascot called Miya-chan, though last I checked the site for the company is dead, so I dunno what happened with that in the end. The only work I can think of off the top of my head where she did the official art herself was for a game called Hometown Story, where she drew some pretty cute creatures, but established she can't get into human anatomy at all.
That's all I know for Pokemon designers outside of what they did for Game Freak.