The Fruit Punch Barrel is an object introduced in The Sims 2: University. It resembles a large pineapple filled with juice. Sims can drink from it by using a cup, or drink directly from the tap. Idling Sims will often do these things as a result of free will, even if their Hunger or Fun motives are not particularly low. A Sim who drinks from a cup will not throw the cup away, but will either set it on the floor or smash it against his/her forehead. If the cup is put on the floor, the maid will not pick it up, and a CleanBot will ignore it.
The Fruit Punch Barrel cannot be refilled, and Sims cannot check to see how much juice is in it. The only way to refill it is to sell the barrel and buy a new one.
The juice keg returns in The Sims 3: University Life as the Glug! Glug! Glug! Juice Keg.