When fed a requested amount of Star Bits, which the amount progressively gets larger as you go along in the game, they will transform into a planet or galaxy with a pink Launch Star leading there. Hungry Lumas can appear both in Rosalina's Comet Observatory and various galaxies. They only turn into galaxies when they are on the Comet Observatory otherwise they turn into planets. Feeding Hungry Lumas is not nessesary to beat either game but is mandatory to collect all the stars.
Hungry Lumas are large pink lumas. They hold a wand in both hands with a Star Bit on top. They have two tufts at the top of it's head that curve slightly outwards. It has black eyes and a dark blue mouth.