The dream is showing you are encountering a spiritual attack, relating to your father and you. These snakes can represent the enemy in forms of sins or temptations or curses. With it being in the flower pot is referring to your spiritual growth. You and your father are trying to destroy what these snakes are representing. I believe with it not being an ordinary snake it maybe linked to something demonic.
Let me know if I can be of anymore help, and thank you!