I know he eats planets, every story i read though that's all he does. 

It's a deep seeded need. He does what he must. It is his sole purpose. It is what he devotes all of his energy and time to doing, because if he doesn't, he starves. Galactus is a cosmic balance, without him the universe becomes in danger of being destroyed. He claims that one day, he will return much more to the universe than he has taken. 

" It's a deep seeded need. He does what he must. It is his sole purpose. It is what he devotes all of his energy and time to doing, because if he doesn't, he starves. Galactus is a cosmic balance, without him the universe becomes in danger of being destroyed. He claims that one day, he will return much more to the universe than he has taken. 

He does spend some time creating his technology, but he only has the time because he has heralds finding worlds for him. 

"

Show some respect. Galactus was the first hypoglycemic comic character.

Wasn't it stated that if he doesn't feed, some other force arrives that can destroy the universe?

" Wasn't it stated that if he doesn't feed, some other force arrives that can destroy the universe? "

So what does he have hobbies like stuff he does in his spare time like play cosmic chess or something with death or some other big cosmic power. 

...I liked it better when he just ate planets to live.