Power
In Princess Mammalia, the young princess initially has no power. She is at the very bottom of the ladder despite her title. Yet, when she is granted beauty, she gains power over all the men in the kingdom. The feeling of power is so addictive that she gets greedier and wants more. Eventually, it is this very reason that leads to her downfall.
Oppression of females
In both stories, women are depicted as being at the mercy of men. In The Princess and the Poacher, the princess is at the mercy of Hengist, her boyfriend and her father. All three dictate the outcome of her future. In Princess Mammalia, the young princess is at the mercy of the men in the kingdom, who consider her only for her beauty, as well as her father, who easily takes away her beauty from her.
Beauty
This is a prevailing theme throughout both stories. Both the young princess and Hengist are very similar in nature, in that they are both treated poorly because of their looks. However, whilst Hengist manages to overcome this and still win the King's approval, the same cannot be said for the young princess, who relies on her beauty to improve her life.