Dollar bills of indeterminate denomination, though typically, a one ($1).
The term derives from the term "Scooby Snack"; from the children's television show "Scooby-Doo, Where Are You!" (1969 -present).
An underpinning of the show's storyline, the main character was often coerced into doing thing he was otherwise reticent to do with the offer of a food identified only as a "Scooby Snack"; if still reluctant, the character was offered more.
The term's implicit secondary association is stripper-to-dog; vulgar.
(Holding a dollar bill aloft and yelling) "Daddy needs a new lap-dance! Who needs a Stripper Snack?"