More Kobolds from Mikmek's tribe.
They could have simply won the war against the mites and took over the caves. Mikmek could be in charge of securing it with a small detachment of Kobolds or he could have rallied any captured kobolds and turned the tide on the Mites. This would effectively make him a hero to his tribe (and a bigger threat to Tartuk's rule).
Goblins could work too if you want to go classic Pathfinder in an iconic sort of way, but I would go with more Kobolds.
