Sprunk is a brand of Soft Drinks in Grand Theft Auto V
It is a lemon-lime flavored soda, the GTA V equivalent to "Sprite"
Vending Machines selling Sprunk Cans are found throughout Los Santos
Slogan
It's the Essence of Life!
Lifeinvader
You can Stalk Sprunk on their Lifeinvader Profile to get a free Can of Sprunk from a Participating Vending Machine.
Link: http://www.lifeinvader.com/profile/sprunk
Trivia
The Ammunation Apocalypse Kit includes Sprunk bottles