Will they run out of rodent species to base these after in future gens? togedemaru itself is based on a rodent called ryukyu spiny rat, yes, but it also looks a lot like a hedgehog, and plusle and minun have characteristics of rabbits. If you are one of those people that count azumarill as a pikaclone, then that line's based both on mice and rabbit.

Will gamefreak's next plush-sealing, pikachu-popularity-riding cutesy electric types be based on some other tiny mammals besides rodents? could we expect marsupial pikaclones in the future?