This is a good question. Let me give you a few examples.
First, the suitors that want the hand of Penelope are extremely greedy. they want to do little and gain much. In other words, they not only want to hand of Penelope in marriage, but they also want to live off of the riches of Odysseus.
Second, we also see greed in Polyphemus. He simply want to eat the men of Odysseus. We can say that his appetite is his greed.
Finally, in some ways we can say that Odysseus is also an example of greed, because he mercilessly kills the suitors. Part of this is due to his desire for revenge, but another part of this is to gain glory for himself. This should not surprise us, as the world of Homer is a world of the desire for glory.