It was released in 2009 by DNA as a freebie from attitude. I don't think it was very stable as DNA discontinued it along with LA Confidential x Skunk. I think you can still get Sleestack x Skunk, OG18 x Skunk and KandyKush x Skunk. Supposedly these strains were all crossed with a male Skunk plant that was well over 20 years old. (old school skunk). I still have a Sleestack x Skunk running that has some of the weirdest smell and flavor i have ever experienced. Sort of mix between grapefruit/skunk/licorice.
Funny thing is I still have the three freebies of the kushberry x skunk as I never germed them yet. been sitting on them for almost 4 years. Was thinking about popping them next round.