When traveling to tinier dimensions, even a skunk with cosmic powers has to eat. The average planet tastes okay, but the greatest nutrition comes from inhabited planets. Don't worry; Prince Wingfire doesn't digest anyone -- at least not permanently. In any case, he absorbs no nutrients from the creatures themselves. What he seeks is the magic of their friendship. As one who wants to keep every universe sustainable, he uses his own friendship magic to protect and restore every creature he consumes.
From the looks of it, Wingfire needs at least ten thousand planets a day to fulfill his hunger. And that's assuming that he doesn't grow any more than he already has. Countless races and civilizations have been greeted by his cosmic uvula, as they get swallowed down the abyss to his stomach. In the end, they find it an honor that they were significant enough to be discovered and chosen for the important task of feeding their new overlord.