Before anyone goes all Betteridge's Law on me, I should point out that the answer is actually yes. The more complex question is why you'd want to, but I can't answer everything for you.
Instructables has the details on how to create your own Jelly -- or, being Americans, Jello -- battery using Jello, Yeast and Carbon paper. As it notes, the Jelly serves as both the casing and fuel source, as the yeast feeds on the sugar while the outer skin of the Jelly keeps oxygen out. Lime Jello Fuel Cell [Instructables via MAKE]