Something so FANTASTICALLY stupid or retarded, it ceases to be fantastic and thus becomes tardtastic! Lengthen the 'A' in tard for a more dramatic effect.
The master of a retard, as commonly seen in public schools since the initial passage of the Individuals with Disabilities Education Act, which mandated the inclusion of retards into standardeducation settings. These retards need constant individual supervision from tardmasters.
"Dude, did you see that retard flip his shit in gym earlier? His tardmaster had to take him down!"