All characters: Ken Ryu (Al) Harry Natsume (Sabrina) Kyou (Koga) Rocket Underling (Rocket Grunt, looks like a mix between R/G/B/Y and pre-BW anime facemask) Lance (Proton) Rocket Underlings (Rocket Grunts, HG/SS) with Delicious Tails (Slowpoke's Tails) Apollo (Archer) What appears to be a Sakaki (Giovanni) poster (?) I suppose it's an Isshu (Unovan) Underling, ex-Rocket member Dr. Fuji Armoured Myutsu (Mewtwo), Sakaki's from anime Yamato (Cassidy) Metamon (Ditto), Mondo's Mondo Musashi (Jessie) Miyamoto Utsubot (Victreebel), Kojirou's Kosaburou (Butch) Sonans (Wobbuffet), Musashi's Rocket Nyarth (Rocket Meowth), in anime an independent member, in games he was Kojirou's and Musashi's Manene (Mime Jr.), Kojirou's Dogars (Koffing), Kojirou's Arbok, Musashi's Dr. Namba Matis (Lt. Surge) Rarecoil (Magneton), Matis' (he wore them like shown on picture) Marumines (Electrodes), Matis' (he wore them like shown on picture) Biriridama (Voltorb) (?), Matis' (he wore them like shown on picture) Katsura (Blaine) Yungerer (Kadabra), Natsume's Lambda (Petrel) Athena (Ariana) Male/Female Rocket Underlings (Rocket Grunts, HG/SS) Delibird, Solicitor's Old Lady (Rocket Scout's), who is not shown on this picture Sabonea (Cacnea), Kojirou's Gingie (Wendy) Utsubot (Victreebel), Kojirou's Kojirou (James) Muskippa (Carnivine), Kojirou's Dr. Shiranui (Prof. Sebastian) Buson (Attila) Vicious/Bishasu (Iron Marauder/Iron-Masked Marauder) Oka (Orm/Oca) Chakra (Carr/Jagura) Saque (Sird/Storc) Silver, as he appears in FR/LG chapters Kamen no Otoko (Mask of Ice, in this form I think known as Masked Man) Siam (Chermaine, Shum, Sham) Kurtz (Keane, Cart, Carl) Red, R/G/B chapters disguise Kotone (Lyra), HG/SS disguise Gold/Hibki (Ethan), HG/SS disguise Wataru (Lance), HG/SS disguise (he also did this in anime) Bashou (Hun) Tatsumi (Tyson) Domino
Oh boy that's sure a lot, but still few are missing! A lot is not tagged, I'm not really sure about tagging policy here, I would even show which one is which if I knew how to. Some are very well hidden, but it's easy to spot them if you take a closer look.
Updated
Possibly the ex-Rocket member living in Icirrus City in Unova (BW)Male and female Grunts holding Slowpoke tails (HGSS)Miyamoto (radio drama)Domino (anime - Mewtwo Returns)Tatsumi/Tyson (anime)Kurtz/Carl (Pokémon Special)Siam/Sham (Pokémon Special)Kamen no Otoko/Mask of Ice (Pokémon Special)Ouka/Orm and Chakra/Carr (Pokémon Special)Vicious/Iron-Masked Marauder (movie 4)Bashou/Hun (anime - Legend of Thunder)Buson/Attila (anime - Legend of Thunder)Shiranui/Sebastian (anime)Katsura/Blaine (Pokémon Special)Fuji (movie 1)Delibird from the Rocket Scout, an old lady not shown in the picture (anime - episode 231)Male and female Grunts (HGSS)Natsume/Sabrina (Pokémon Special)Matis/Lt. Surge (Pokémon Special)Dr. Namba (anime)Possibly a Sakaki/Giovanni poster (HGSS)Athena/Ariana (HGSS)Lambda/Petrel (HGSS)Apollo/Archer (HGSS)Lance/Proton (HGSS)Gingie/Wendy (anime - episode 231)Armored Mewtwo (movie 1)Saki/Sird (Pokémon Special)Silver (Pokémon Special)
This outfit appears in the FRLG chapter.Team Rocket Trio (Pokémon Special)
Ken
Ryou (Al/Ryu)
HarryGrunt (RGBY)Kyou/Koga (Pokémon Special)Kosaburou/Butch (anime)Yamato/Cassidy (anime)Musashi/Jessie (anime)Kojirou/James (anime)Wataru/Lance (anime)Lyra and Ethan (HGSS)Red (Pokémon Special)Mondo (radio drama)