Donald Duck universe
Donald Duck and his maternal uncle Scrooge McDuck received nearly equal exposure in comics. Other primary characters include Donald's three young nephews Huey, Dewey, and Louie, and girlfriend Daisy Duck.
Mickey Mouse universe
Huey, Dewey, and Louie are the three triplet nephews of Donald Duck. They were originally a catalyst to provoke Donald's temper, but they later became resourceful and helpful.