Underneath the BLU spawn on the Banana Bay map is a summoning circle made up of toxic waste, candles, and a large collection of bananas. The circle was created to summon Poopy Joe, the first American Monkeynaut in the game's storyline, who died in his rocket moments after launch due to its Australium fuel supply (a mysterious metallic element first introduced in the 2010 Team Fortress 2 comic "Loose Canon") having been maliciously switched with gravel water by Mann Co., who was supplied America's entire stock of Australium fuel by the United States government in the first place.

Underneath the RED spawn on the Banana Bay are two conveyor belts that appear to be used for converting dozens of bananas into Australium bars.