Mystery Machine The Skin Cells

Who is that in the Mystery Machine?
I saw some kids in the Mystery Machine
And I thought it was
Scooby and Shaggy
Scooby and Shaggy
Scooby and Shaggy
Scooby and Shaggy
Scooby and Shaggy
Scooby and Shaggy
Scooby and Shaggy
Scooby and Shaggy

Oh, who's that kid with the scary mask
Yeah, who's that kid with the scary mask
I thought he was
A real monster
A real monster
A real monster
A real monster
A real monster
A real monster
A real monster
A real monster