É - porque os nibblonianos são maiores por dentro , e seu sistema digestivo é de alguma forma capaz de manipular a gravidade ou mover a massa do seu conteúdo através de outra dimensão.
Formulário de trecho artigo do Nibblonians no theinfosphere.org (grifo meu)
[…] As waste, they excrete pellets of dark matter, an extremely heavy material formerly used as a starship fuel. The mechanism by which meat, which is made of ordinary matter, is converted into dark matter inside the Nibblonian advanced digestive tract is unknown, although it can be assume it may be based on a kind of black hole or pocket dimension which would explain their ability to eat much larger creatures whole and not visibly gain any weight. They are capable of swallowing themselves to enter their digestive systems and get out of a universe. The Nibblonian eyestalk is capable of emitting several types of energy that can wipe memories or burn skin.