The most obvious one is
His claws peep through like Rays of Light
It is kind of an odd comparison, but it is a comparison. His claws come out like rays of light means that the claws are barely noticeable as he unsheathes them. They are however like the first light of dawn or the last light of dusk. He's sort of checking them to make sure they are there.
Who and that are Relative pronouns
