Can you please tell me if my last sentences are possible?

What does "to be a snake" mean?
Does it mean Jason is unfriendly to Storm?
1) Mickey is late because he’s got the wrong room number on his timetable.
2)He apologises to Mrs Winter for being late.
3) She tells him not to arrive late again. They are doing jazz dance today.
4) Jason is unfriendly to Mickey and asks him if he can’t tell the time. Storm says he is a snake.
5) If you arrive late for classes, your parents will have to justify (motivate) your delay otherwise you are not admitted into (?) the classroom.
6)I haven’t got my dictionary. Don’t worry. I can lend you mine this time but remember to pack (?) it in your rucksack next time.

Thata expression "to be a snake" means h is a threat and could strike at any moment.

5. justify is good but motivate is not

Sra