Flame Princess

Flame Princess has a volatile personality; she usually has a calm demeanor, though with rather frequent tendencies to sudden and violent mood swings. She is described as "passionate" by Finn, "evil" by the Flame King, and "intense" by Pendleton Ward. The Flame King also remarks that she is difficult to control. She seems to be very sensitive and quick to judge. She is also prone to unprovoked fits of aggression, as shown when she throws fireballs at her subjects just for whispering. Flame Princess is also impressionable in a positive way. She is very happy when Finn calls her beautiful. She was also interested when Jake was giving her gifts in the episode "Incendium" and excited when her dad let her date "Prince Finn," though this excitement quickly turns to anger when "Prince Finn" rejects her.

In the episode "Hot to the Touch", Flame Princess shows curiosity about her new surroundings by examining flowers. This sets them on fire and she seems a bit surprised by the reaction, indicating she does not know much about lands other than the Fire Kingdom. At the end of the same episode, she shows that she likes Finn, but thinks that they cannot be together because they are opposite elementals, calling Finn "a Water Elemental because of the tear that she felt from him.

In "Burning Low", she seems to be calmer and able to handle a part of her flame being doused. This is illustrated when Finn jumps into the water while his foot is on fire, but she does not visibly react. This was also shown in "Vault of Bones" when Finn tossed a lit torch in the water, she does not show any signs of pain even though it was her who lit it. That may be due to Finn and Flame Princess getting used to each other.

In "King Worm", an introduction to Flame Princess's impatience is made when Finn refuses to have the soup that she was offering him. She instantly orders him to "eat it now!" in response to Finn telling her to wait.

In "Vault of Bones", Flame Princess is shown to still have a desire to be destructive, even though she says she'll only destroy evil things. Flame Princess's impatience is also made known, getting bored whilst Finn was searching around in the Vault.

In "Jake Suit", she is seen calmer and able to control her anger well, even though Jake, who is controlling Finn, embarrassed him in front of her less evil family by making him dance his Baby Finn song. When she figured out the bet, she should have shouted at him, instead she thinks it is pretty hardcore of Jake to do that, then she wishes Finn good luck.

In "Front & Fire", she dislikes it when someone insults her relationship with Finn, shown when she battles Ice King because of the letter she thought was sent by him. It is proved in this episode that she can lower her anger levels even more, which is seen when she did not rage at Finn for hurting her feelings when he admitted he wrote the forged letter. However, she was heartbroken at this fact.