A Pickle Monster is a mutated pickle. They were created by Theodore Pickleson, and they are used as soldiers in the Pickle Land army to make up for the fact that regular pickles are so small and unable to do much. They are efficient attackers, destroyers, and killers, but they are addicted to eating bombs, so they're not the brightest of fighters.
Pickle Monsters are created by taking a pickle, and passing them through a series of mutations, genetic alterations, and stinky gas. When the process is finished, they will be MUCH larger, and strong enough to crush a lamppost AND MORE!
Pickle Monsters are some of the most powerful mass-produced creatures on Earth. Unfortunately, Pickleson only made twenty of them before he got a rash from the chemicals he used to make them, and shut down the operations completely. The pickle monsters that were made are kept in the Pickle City's Underground Caverns, where they await their next mission.
Becoming a pickle monster extends the longevity of a pickle from 300-1000 years to over 10,000 years. This why so many pickles volunteered to be turned into brutish beings.