Wario's mother first appears in a flashback by Wario, where she and her husband berate him for being so pathetic.
As Wario, in the form of the Wario Head, tries attack SMG4, the Mario Head reminds him that "the accident was thirty years ago", and that he has to let his mother go. Upon hearing this, Wario has a flashback to the moment his mother died, causing him to shed a single tears.
Wario mentions her to his brother to calm him down and solve the situation.
- Wario's Mother is the seventh character whose death was taken seriously, the first six being King Bob-omb, his son, Desti, Francis, New Super Duper Mario Plus Ultra and Greg The Alien.