A tightly rolled up towel, tiny tooth brush, boot brush or anything else your DI tells you. Used in Marine Corps boot camp by "this recruit" to polish or clean floor while running holding the towel in front of them hard to floor. Usually in most cases being barked at by the DI's war.
someone who is a super-huge monster scrub, someone who perfectly epitomizes every possibledefinition of scrub, and sucks at life sooo hard that they dwarf all other scrubs and could come out of the ocean and destroy the scrub city with their scrubliness.
Person 1: Janee got arrested, kicked out of school, lost her job, and moved back in with her parents.
Person 2: Damn what a SCRUBZILLA!