Grugly

To do something in an especially cool, brutal, or excessive manner that would make your cavemen ancestors proud.

If it is something that makes you want to shout "UNGA BUNGA" as you do it, it is grugly.

Best used as an adjective or adverb.

"That 800 damage True Charged Slash I just landed to knock the boss over was ESPECIALLY GRUGLY."

"Eating 3 pounds of ribs in one sitting? Very grugly."

"What a grugly punch, I think he actually caved that guy's face in."