Season 4 moves beyond the core trio of Catboy, Owlette, and Gekko by introducing , a space-loving boy who becomes a hero after an asteroid incident.
: A scientist-hero who aids the PJ Masks during space missions, though he sometimes struggles with the physical side of hero work.
: To combat these threats, the team debuts the PJ Jet for sky missions and the PJ Sub for underwater battles in the newly introduced Crystal Garden .
: The dragon girl of Mystery Mountain continues to play a vital role, often guiding the team through magical challenges.