The Flying Dutchman's mom is a green ghost who wears a green shirt with a light green skull on it, a black vest, green arm rings, glasses, and a bandana with dark purple dots.
According to the Flying Dutchman, whenever his mom visits him, she cleans everything, including his ship and the Flying Dutchman himself, but before the latter's mom goes on a cleaning spree, she needs to lecture him which just goes on and on.
SpongeBob once made the Flying Dutchman clean his ship and himself so then his mom would not have to lecture him when she visited.
The Flying Dutchman's mom has a friend named "Killer," who is a blue ghost on a green motorcycle.
She thinks anyone who is not filthy is a "clean freak."