Arcane Propulsion Armor can give additional body parts to the wearer instead of "missing" ones:
If the wearer is missing any limbs, the armor replaces those limbs—hands, arms, feet, legs, or similar appendages. The replacements function identically to the body parts they replace.
An artificer provides such an armor to a naga. Naga has no legs, so it is missing them. Will it get legs from the armor?