When it arrives on board the mining ship "Red Dwarf" in "Polymorph", the Polymorph attacks the crew by turning into a ruthless monster to drain Lister's fear, a beautiful woman to drain the Cat's ego, a duplicate of Rimmer to blame Kryten for the Cat's condition and thus extract his guilt, and Rimmer's mother after having sex with Lister to provoke Rimmer's rage. It is eventually defeated when two heat-seeking blaster bolts that the Cat had previously trapped in an elevator are released once again, the bolts destroying the Polymorph in its monster state and its death restoring the crew to normal.