NPCs (Non-Playable Characters) shouldn’t be ugly Sims! Replace your Vendor NPCs with these fully dressed, unique Sims. No CC (custom content) is necessary or mods. Vendor Sims are those Sims that work in the stalls that come with a variety of packs.
PACKS THAT ADD VENDORS/STALLS: Cats & Dogs, City Living, Jungle Adventure, Seasons, Island Living, Discover University, Eco Lifestyle and Snowy Escape.
NOTE: It is not necessary to add vendors for each pack that you have. You only need 1-2 sets. I simply made sure that each pack was represented. Whichever vendors you use will show up at all stalls throughout the world.
I have instructions on my NPCs For Your Game page to help install, find more or make your own NPCs.