Possibly. Dwarf cories are cute little guys and since they're mainly bottom dwellers, they may not pose a threat to a dwarf puffer. DP's are kinda like bettas; some are more tolerable of other inhabitants than others. Dwarf cories only grow to 1"-1 1/4" so would be suited to your tank, stocking wise. My dwarf puffer females didn't bother my little cories, but that may have been b/c the one female was busy chasing the other! People have stuck dp's in their larger community tanks made up of tetras, livebearers, etc. and seemingly had no problems. The key there may have been a larger tank, seeing as how puffers are territorial. You could try a couple of tetras with a dp, but whatever fish you have, be prepared to move them if there's a compatibility issue.