Susan Irvine is the secondary antagonist of the 1990 movie The Witches.
She was played by Jane Horrocks, who is also voiced Babs from Chicken Run and Fairy Mary from the Tinkerbell film series.
She first makes her appearance when she arrives at the Hotel Excelsior with Grand High Witch, the ruler of all the witches. There they meet Mr. Stringer, hotel manager and character, and the other witches. Then when Grand High Witch performs black magic on a child, in a painting, Susan is about to do magic on the picture but Grand High Witch loudly orders her to come, saying: "Irvine! Irvine!" She later appears with Grand High Witch and the other witches at their meeting at the hotel.
She calls out a witch, who comments on Grand High Witch's plan to destroy all the kids of the world, saying, "She did!" Susan also stays with Grand High Witch and the other witches while they transform Bruno Jenkins into a mouse. Irvine also goes with villains to capture Luke Eveshim, child and main hero, and then turn him into a mouse.
Later she says to Grand High Witch that Herbert Jenkins is Bruno's dad. When she is helping her in their room, The Grand High Witch demands who's knocking and saying, "Miss Ernst!" She says irritated, "Who is it?!" and Susan says, "You told them to come up after the drinks." Grand High Witch replies, "Alright let them in!" Then later Grand High Witch asks, "How is the room service here?" "Diabolical," replies Susan Irvine.
After Grand High Witch says, "Good." Then Susan asks, "Who do you know that old woman upstairs?" But Grand High Witch cuts her and barks orders to villains saying, "Come come the elevator is out of order!" When the villains are making their arrival to the restaurant part of the hotel, She asks Susan, "What are you doing here?!"
Susan says, "The Banquet Miss Ernst." Grand High Witch then says, "No no you must go to your room!" Then talks briefly and manipulatively to Mr. and Mrs. Jenkins and then Susan says, "But it's our banquet!" Grand High Witch replies, "You are not here to enjoy yourself you are here as my staff go to your room!"
Angered, Susan says, "I quit!" Then she later stays alone in their room she never wanted to be one of them anyway. Later after the villains are destroyed and defeated, she smiles quietly as the heroes give Bruno back to his mom and dad and then they leave. The next day, Luke gives Susan their home address in the United Kingdom and his grandma and heroine, Helga Eveshim, gives it to him but doesn't understand.
As they leave the Hotel Excelsior, she smirks happily again while looking at their address, which Luke gives her. Then close to the end, she comes to them at their place, in the United Kingdom, and transforms Luke back into a human and gives him back his glasses and mice. She even reveals to them that she no longer needs gloves and has pretty hands now because she's a good witch. She then leaves to repeat the same process on Bruno.