Forty-Seven Hour Energy Bar is an invention the other jokers made for Sal. This is featured in Look Out Below as a Joker vs. Joker Challenge against Murr's invention, the CanTenna. The 47-hr Energy Bar is a giant sized candy bar.
It allows the eater to have energy for forty-seven hours, but they must eat the whole bar. If they want half the energy time, they eat half the bar. Murr argued that the bar is too big and cannot fit in your pocket and Q in the background said that it can't even fit in your stomach. However, Sal was able to score a Win.