A sea monster in your dream can represent your subconscious fears, especially those that seem bigger than life or overwhelming.Dreaming that a sea monster is after you can mean:
You feel or fear a particular problem is closing in on you in real life
You're afraid that something or someone will overwhelm you in your real life, out of your control
You're afraid some event will catch you off-guard, especially outside your element or your area of expertise
You're having a Toxic Dream