Mrs. Wyatt worked in military robotics, but she gave it up to focus on raising Jason. When she saw what she believed to be mistreatment of Jason by Velma's Mystery Inc. friends, Mrs. Wyatt plotted to break up the group; using her skills to build a robotic dog to cause a rampage and frame Scooby. Her creation appeared during a tour of Crystal Cove led by Velma's mother, and tore through the tour bus. Mrs. Wyatt's plan works, as Scooby is set up and taken to a prison for the most diabolical animals (with Professor Pericles as one of the inmates).
The group met Mrs. Wyatt when they went to her home under the belief that Jason was behind the building and operating of the robotic dog. The accusations towards Jason further angered his mother, leading the twisted villainess to send her creation towards the group to destroy them. The appearance of the robot cleared Scooby, and it was in the episode's climax that Mrs. Wyatt was revealed as the evil mastermind after the robotic dog was destroyed by Fred and Scooby. Mrs. Wyatt boldly admitted to her scheme, stating that her plan was to separate the group so Jason could have a clear chance at Velma, but decided to destroy them (Velma included) after Jason was questioned. Mrs. Wyatt was arrested by Sheriff Bronson Stone, and led away in handcuffs while continuing her rant.
- "I saw how you treated my Jason at school, so naturally, I did what any mother would do. I built a demonic robot dog to destroy you! I framed your little doggie friend to break you up, leaving Jason a clear shot at his true love. But when you showed up and blamed him of all things, I decided to get rid of you all! I gave up a career in military robotics to raise my son, not to watch him get picked on!" (Mrs. Wyatt revealing her evil scheme during her arrest)