The Robot is Romeo's self-created personal servant and the sole antagonist of the series. His most notable ability is his very long and stretchy arms which are often used to quickly get Romeo from place to place. It is around 3-4 times larger than Romeo. It is one of the few inventions made by Romeo that has the ability to speak.
An alternate version of Robot named Robette was introduced in "Catboy and Gekko's Robot Rampage".
Robot can stretch his arms and legs and has the ability to speak, developed by Romeo.
Robot is very respectful and performs tasks for Romeo and brought from place-to-place. Similar to how Luna Girl is with her moths, Romeo tends to mistreat him and acts stubborn towards his warnings about the PJ Masks although he does sometimes treat Robot with kindness. It is possible that he is the only friend of Romeo.