gobble someone or something up
to eat someone or something completely and rapidly. The wolf said that he was going to gobble the little girl up. The wolf wanted to gobble up the little pig.
gobble something down
to eat something very fast, swallowing large chunks. The dog gobbled the meat down in seconds. The cat gobbled down the sardines.
gobble something up
to use up, buy up, or occupy all of something. The shoppers gobbled all the sale merchandise up in a few hours. They gobbled up everything.