In the books, who is Tyson?

Well, you can call him a half-blood brother of Percy. Why? Because he's a son o' Poseidon. Not with a mortal but a nature spirit. So Tyson's not a real demigod after all (becuz a demigod = a god x a mortal). He's a cyclop. People call him monster. Maybe he is. But a good one, indeed. He's helpul to Percy...

He's a cyclops and Percy's half-brother. His father is Poseidon, his mother a nature spirit. Now I could give you a detailed description of his character and achievements, but I don't want to spoil you to much. I recomment you read the book and form your own picture of what he's like. It's much more fun ^^