Episode 13 of "Futurama"
s02e04 Fry and The Slurm Factory

Fry becomes addicted to Slurm, the ultimate drink in year 3000. When a contest appears on TV saying that the person that finds the golden cap in one of the cans will win a free trip to the Slurm factory, Fry uses an F-Ray gun that can see through metal. When he wins, he and the gang go into the tour, but Fry falls into the Slurm river followed by Leela and Bender. After being sucked by a drain, they arrive to the real factory where Slurm comes from the behind of a giant queen slug. When they try to escape, they are saved by Slurms McKenzie, the party slug and Slurm mascot. Prof. Farnsworth wants to tell the world of their discovery, but Fry convinces him not to so Slurm can still be produced.