User blog comment:Magma MK-II/Characters that shouldn't be here, Part 4: Electric Boogaloo/@comment-366087-20160122072505/@comment-26884760-20160125184813

actually Fat Buu and Super Buu are just aspects of Kid Buu with people absorbed.. Kid Buu is the only "true" Buu but maybe I'm just being picky on that part..

Fat Buu = Kid Buu after absorbing a Grand Kai (I believe)

Super Buu = Kid Buu after absorbing Fat Buu (Evil Buu is still Kid Buu, just weaker)

Kid Buu = completely "pure" Buu, with no other beings absorbed into him.