In my game, I need an NPC party made of fey. For game reasons, they need to be creatures that started out not very powerful (about CR 3 or less and CR 1/4 is fine) and have grown powerful through adventuring.
They will be fighting the PCs at level 16 or higher, so I expect that most of them have a lot of class levels, although an advanced form with a lot of extra natural hit dice is possible, if that development is plausible on the timescale of PC leveling.
A mixed race party is also possible and probably likely. (Good fighter races rarely are also good caster races.) There will definitely be a straight up fight, although some previous indirect interaction is possible.
What would work to make a good party?
Fine print: I am running the original pathfinder, not the playtest. 3rd party sources are fine.
I've seen an atomie magus (spiderhawk archetype; 3rd party) in play. She was a solid melee character. Also a useful missile weapon for the sorcerer with telekinetic charge that I was playing.