In Curse Of Strahd, Beans' forms were always ghastly or misshapen in some way, which Mormeros made to creep out other members of Heralds of Dawn. This worked especially Pip, where they would form a dark rat counterpart named "Pop".
While Beans proved useful as a scouting tool, Mormeros did not have a long relationship with the Spirit. He died not long after learning how to summon them, and Beans' spirit was trapped in Barovia until the Slaying Of Strahd.