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Those exist. you can go to http://play.pokemonshowdown.com/sprites/trainers/ for the names of all available sprites to use and use /avatar <avatarname> to use them on PS.
For example, /avatar zinna will give you the zinna avatar, and /avatar teammagmagruntf-gen3 or teammagmagruntm-gen3 will give you the different magma grunt sprites.