Gary seems to be a floating mermaid made of bone. Her hands are connected to her hair. She has gigantic white eyes and hair that resembles Marceline's, and a long, slithery tongue. Finn describes her as ugly.
Gary can float, spit black, and create blue flames from her hands.
Behold, the beautiful mermaid of the river! Which one of you mortals wants to mate with all this?
Remember to save the brain for dessert!
- Gary's hatchlings do not resemble her; instead, they look like baby birds or chicks.
- This may be because, instead of being a mermaid, she may be a siren. A siren is a half bird, half human Greek mythological creature. Sirens sometimes vary in forms, such as half fish or full woman body, making recognition a bit difficult.
- Gary does not really resemble a mermaid.
- This is further disputed, as she has legs instead of fins.
- This means that she is possibly a Siren.
- Her saying "Which one of you mortals wants to mate with all this?" was censored.
- The Goblin King finds a mermaid girlfriend, and supposedly, Gary is still the ruler of the mermaid even though the two look nothing alike.