The next level up from being a mook. Some would call one who is a "mookanightus" the king of all mooks. Ussually drinks shitty vodka such as wolfschmidt or dubra, and uses it to lure under-aged girls to a even shittier car (such as a 1980's model purple/ moave honda civic. Tends to work at Lucy's Chicken, and has been known to fish for long periods of time. Main goal in life is to procreate, get shitted, and spread stds. Also see STD-K
Person A: Dude that kid Kyle DK is such a mook, I cant believe he drinks that shit and lures girls into his civic with it.
Person B: Nah dude, hes past the point of being a mook. He has entered the level of MOOKANIGHTUS.
Person A: Shit dude, I didn't realize. I better go hide my younger sister.