Whilst the rest of them girls bicker it out, maybe I'll throw a bit in.
How was the snakes behaviour before you got him?
Is the aggressive/defensive behaviour confined to the Viv or does he display these traits as well when you have him out of his Viv?
Just noticed that you have him in a tank with a wire mesh lid. If the tank is open on all sides and basically an open roof, the snake is going to feel very exposed. This will result in a stressed snake who is always in a defensive/ vulnerable mood resulting in strikes which are misconstrued as aggression.
Guessing the age of that snake going by the pics I would say he looks around the two year mark. Two adult mice every seven days should be ample to keep his appetite sated. Don't go throwing him mice like you would throw baps to a bear.
Chances are he is still acclimatising to his new surroundings and you are a new threat. Persevere, make his tank a lot less exposed, get him into a wooden Viv and after time you should see a calming in his behaviour.
On the other hand you could just have a typical narky Cali. I've seen plenty of them in my days, not that that is the norm with Cali's.