Alrighty, if i'm not mistaken: Chimchar, Sableye, Alakazam, Totodile, Honedge, Cyndaquil, Vulpix, Eevee (Leafeon), Riolu, Houndour, Shinx, Cubone, and Noibat are all in. I wouldn't want to say "taken" though because i'm totally fine with seeing more than one of these in the rp, you don't have to compromise if one of your favorites is already being used.

Someone'll most likely correct me if the list above is wrong in any way, but thats the vast majority of what species are in use right now.

Edit: i'm 100% no one is using Nincada so go for it c: