这孩子不是肚子饿，就是馋嘴。

The boy cannot be hungry; it is sheer greedy.

也许尝尝“饥饿的青蛙（馋嘴蛙）”？

It's just green pepper. Maybe some hungry frogs?

你这个馋嘴！你已经吃了两份了！

You greedy pig! You've already had two helpings!

就象一个馋嘴跟着一个猎物，但又不显出有意这样做的神气。

One would have said that it was an appetite following its prey, and purposely without wearing the air of doing so.

鸭子坐在巢中孵蛋所付出的时间物有所值，这不仅仅是为了对付那些偷蛋的馋嘴狐狸。

All that time ducks spend sitting on their nests pays off, and not just by protecting their eggs from hungry foxes.