The Banana Replicator is a Special Item in Bloons Monkey City. It is obtained randomly in treasure chests. Once obtained, the very first Banana Farm the player gets will have its City Cash capacity increased by 150. This allows the player to earn more cash when they exit the game for long periods of time.
This item also exists as an Epic trinket in Bloons Adventure Time TD. It doubles cash from all pops by the wielder. It can be equipped to any character.