That's a California king snake, the striped version; there's also banded ones, albino versions & desert phase, so your confusion is understandable as there's so
many variations, including some with crazy markings (dots & dashes) when you mate a banded with a striped. They are often quite nervous snakes, especially
when young...it's typical & doesn't mean he won't outgrow it. As I said, just be patient.