The Shrinker is one of Romeo's many inventions. It was created for the purpose of decreasing the size of its victim to however small Romeo wants, and to decrease the size of any object in the city.
In "Catboy and the Shrinker", the Shrinker was operated by Night Ninja and the Ninjalinos as Romeo pushing the buttons and drove the vehicle around. Catboy was the only PJ Masks member to be affected by it. However, the PJ Masks managed to shrink it and disappeared for good.
In "Moon Prix", the Shrinker was possibly recovered or rebuilt by Romeo and was seen using the invention to shrink Catboy's Cat-Car as a prize for who won the race that Romeo had set up.
