Wee know that Piccolo Junior was initially seen as an infant upon his first appearence but then he changed significantly in those 3 years... but then his development was decreasing significantly over time, to the point he didn't change in the 10 years after the Boo arc. Would he even age with time? Is this specific to Piccolo, since he's a reincarnation, or maybe all the Namekian warriors share this strange maturing?