Elbow Princess makes her first appearance in the episode "Princess Monster Wife." Her head appears to be an arm, hence her name. She is one of the princesses to have a missing body part in the episode, which was a small part of her right hip. She also appears in the episode "Princess Day" where it is revealed she is considered a registered princess by the chair of princesses.
She has a right-hand arm sticking out of her head that bends to her left side. Her skin is a grayish blue-green and she doesn't have a neck. She has a golden band around her head just before her arm that has a diamond-shaped ruby in it and that is probably her crown, she is the only princess with a different crown due to her being an arm. Her dress is a floor length pink V-neck that has a red ochre-colored design around the bottom.
- She is one of the Ice King's favorite princesses, as shown in "Princess Monster Wife."
- Ice King used her hip to make Princess Monster Wife, instead of her obvious part, her elbow.
- Although the Ice King states that Princess Monster Wife has Elbow Princess's hips, he only stole one of her hips and not both.
- The arm on her head matches the expressions she has in the episode "Princess Monster Wife" when she was yelling and freaked out the arm on her head went up like a freaked out person would do.
- As shown in "Princess Monster Wife," she can bend the top part of her up straight when she is talking.
- Apparently, being a giant arm with limbs is not a result from a Magic Man trick.