The Ninjalinos are the Night Ninja's henchmen that assist him during his plots.
Like their boss, Night Ninja, the Ninjalinos are very fast and agile. They have proven to be very difficult to get a hold of, which often creates frustration among the PJ Masks. Along with their physical ability, the Ninjalinos use colorful gooey balls known as "Sticky Splats" to pin down their enemies. They will also use other weapons (such as light poles) as battering rams.
The Ninjalinos are very obedient towards Night Ninja's orders. They don't speak in the English language and instead mumble, sing, or laugh. They will also follow in Night Ninja's emotions such as the time he nearly cried in "Owlette's Two Wrongs" because his statue was ruined by Owlette.
In "Owlette and the Owletteenies", they finally grew sick of Night Ninja's constant demands and criticism and decided to join Owlette. For that episode they were deemed her "Owletteenies". They eventually became disobedient towards her and went back to Night Ninja's service.
The Ninjalinos all wear fully-covered ninja costumes, similar to Night Ninja's. However, their outfits are a dark purple color as opposed to Night Ninja's being dark blue.