Madam Mouserinks, known in the English release of Nutcracker Fantasy as Queen Morphia, is the primary antagonist of the 1979 stop-motion anime. She is the two-headed queen of the mice and leads her forces in a war against the Doll Kingdom. Her background originates in the long-standing conflict with the kingdom, and she is driven by a desire for power and vengeance. After King Goodwin refuses to agree to her demand that his daughter, Princess Mary, marry her son Gaar, Madam Mouserinks retaliates by placing a curse on the princess, causing her to take on the appearance of a hideous mouse and fall into a deep, enchanted sleep from which she cannot awaken until the king consents to the marriage. This act establishes her as a cruel and vindictive figure who uses dark magic to achieve her goals and punish those who defy her.

Her personality is malevolent, manipulative, and ruthless. She commands a vast army of mice and exerts control through fear and sorcery. Her primary motivation is to expand her dominion and force the surrender of the Doll Kingdom. She derives her power from a magical artifact known as the Nut of Darkness, which must be destroyed in order to break her hold over the kingdom and lift the curse on Princess Mary. In her confrontations with the protagonist Clara and the nutcracker Franz, she demonstrates a willingness to use force and intimidation, ordering Clara to hand over the nutcracker doll and later pursuing Franz out of vengeance for the death of her son. Her notable abilities include shapeshifting or physical transformation, as she appears as a two-headed creature, and the capacity to cast powerful curses that alter the forms of others. She is also capable of commanding her mouse minions and maintaining a stronghold of dark magic.

In terms of key relationships, she is the mother of Gaar, who serves as her heir and general in her war efforts. She holds deep enmity toward King Goodwin and the entire royal family of the Doll Kingdom, as well as toward Clara and the nutcracker Franz, whom she transforms into a nutcracker doll after he destroys her source of power. She does not undergo significant character development during the story; she remains a static, purely antagonistic force until her defeat. Her eventual demise occurs when the Nut of Darkness is shattered by Franz, which causes her to lose her power and die. However, even in death she manages to place a final curse on Franz, turning him into a nutcracker. This act reinforces her role as a vengeful and spiteful figure who refuses to relent even at the end.