The Powerpuff Girls, e.g (4)
(Other definitions for trio that I've seen before include "Group of three (musicians)" , "Beethoven's 'Archduke', for instance" , "Piece for three players" , "Work for three" , "Three together" .)
(Other definitions for triad that I've seen before include "Group or set of three" , "Chinese secret society" , "Could be major" , "Chinese criminal society" , "Union of three" .)