He and two other Ferengi helped Ulis in an attempt to pillage the Enterprise NX-01 after they had rendered its crew unconscious.
After being awakened by Tucker, who was unaffected by the anesthetic used by the Ferengi, T'Pol was able to convince Muk that Ulis was trying to rob him of his share of the profits. His greed led him to trust Tucker, who led him, Ulis, and Muk into a trap, where they were ambushed by T'Pol.
Upon recovering, Grish and the other Ferengi were forced to carry all the items they had loaded onto their own ship back aboard the Enterprise. They were then allowed to leave aboard their vessel, with Krem, the Ferengi who was treated with disrespect by the others, now in command. (ENT: "Acquisition")