Hubert spends the majority of the Creature Shop film Rat embodying the title. In rodent form, Hubert is a small white rat with certain markings (since according to Conchita, it's only natural that a white man become a white rat). While two live rats, including one named Nutter, played the character for the majority of the shots, multiple Creature Shop versions were created
The primary rat was a fully animatronic creature, with servo-operated jaw and whiskers. A more limited servo-oeprated "wriggling rat" was used for scenes where Hubert is being held or hung up on a rack or otherwise suspended. A basic prop "stunt" rat was made for the washing machine sequence and cylindrical "bullet" rat for scenes where the creature is being dragged. A more refined stunt rat was developed, a detailed copy of the main rat and with a basic mechanical device to simulate breathing and movement, but without the full articulation of the fully animatronic rat.
In the "behind the scenes" featurette accompanying the film's DVD release, star Imelda Staunton talks about her rough treatment of the rat. A bandaged, animatronic Hubert, with an IV, is shown lying in the Creature Shop, holding a sign and threatening to sue.