Toadd (formerly Mario) used to be the "hero" of the Mushroom Kingdom (now Toad Hell) and an enemy of Toad. He tried to hide the stars from Toad during Toad-megeddon, but since Toad's face was on everything he could see where Mario hid the stars. It was pointless. Mario couldn't see the Toad faces because he was blind because his eyes were replaced with Toad faces. The Toad Faces didn't tell him about their presence because they wanted to undo all his hard work and hurt his feelings.
He's gonna appear in the upcomming v3 of Releasio Fighting.
Pre Toad-megeddon Edit
As stated before, Mario was the "hero" of the Mushroom Kingdom before the Toad-megeddon. He was also a plumber, and he had a partner. The partner was Luigi. Mario believed Luigi was his brother, but really Luigi was a space deity who was pretending to be Mario's brother for reasons unknown to any.
They have a plumbing company they ran together (Mario Brothers Plumbing).