To have sexual intercourse unromatically.
If you are having sex with your new girlfriend and your brother kicks the door open while he's buck-naked and asks you where the pickled eggs are...
You are getting your skrogg on.
To have sexual intercourse in the style of an 80's glam, hair-metal band. Has faintly Nordic connotations.
Dude, I, like, totally saw Gunnar skrogging that blond after the Metallica concert... their hair got tangled together and someone had to cut it.