Without divulging too much, let me share some of what I've learned from Giant lore. Giants are very large and very powerful. Everybody knows this. In many traditions, Giants came from breeding between gods and humans. If you can remind those who serve Giants that they are or used to be human, you're half-way home.
Giants are very hungry.
In a pinch, they'll eat whole cattle, sheep or goats. Giants have bad eyes. They live in the dark, they have only one eye, or they can't see very far. They have great difficulty seeing or understanding the effects of their Gigantic powers on human beings and small communities. We need to amplify the human consequences of Gigantic folly, greed or carelessness.