WARNING! This article contains minor SPOILERS for That '90s Show season 1!That ‘90s Show subtly references Kitty’s dog Schatzi from That ‘70s Show, but makes the mystery surrounding his fate even more peculiar. After starting menopause in That ‘70s Show season 5, Red decided to cheer Kitty up by getting her a dog, hoping it would help relieve her sadness over not being able to have more children. Kitty immediately fell in love with the little Dachshund that she named Schatzi, but the dog followed a common sitcom trope by frequently disappearing from That ‘70s Show and inexplicably reappearing. Schatzi’s fate thus became one of That ‘70s Show’s greatest mysteries, which That ‘90s Show expands on.

https://screenrant.com/that-90s-show-schatzi-dog-mystery-weird/