He is a newer genie, so he isn't the best with granting wishes. However, he granted Rubble three wishes, which mainly involved pup treats.
Jeremy has brown skin with dark brown eyes and hair. He wears a red fez hat, a red vest, and baggy yellow pants with a purple waist. He also wears red pointed shoes. Appearantly he is not taller like the adults at all.
This is a gallery of Jeremy's attires: