Marceline fought The Fool centuries ago when she was on a mission to protect the remaining humans from vampires. While most vampires are malevolent, The Fool is more of a mischievous child; in one of his witless misadventures, he lost one of his fangs to a box turtle. Despite this, he is still a vampire which means he subsists on human blood. He is one of the first vampires Marceline ever targeted, and while she hunted him with deadly earnest, he regarded the whole thing as a game of tag. Marceline managed to defeat him and gain his power of flight and levitation.
The vampires are resurrected after Princess Bubblegum removes Marceline's vampire essence from her. After a short period, the Vampire King and his court manifest. While the other members of the vampire court debate what to do, The Fool proposes taking things easy, suggesting that they just get an apartment. Most of the court part ways with the group, but The Fool hangs around with the king.
The Fool is the first vampire Marceline kills in stakes in Vamps About. Marceline dispatches with him with absolutely no effort. The Fool casually shrugs off being stabbed in his usual carefree fashion.
The Fool has the body of a gnome with long, noodly limbs on a short, round frame. He has a Petit Goatee style beard, a single fang, light blue eyes with diamond-shaped pupils, and dresses barefoot with a grey, long-sleeved shirt, dark, navy pants dress, and a similarly colored pointy hat.
As a vampire with magical powers, the Fool can levitate and fly by his own means.
- He is named after the unnumbered trump or Major Arcana card in traditional Tarot decks. The Fool card represents innocence, spontaneity, and free-spiritedness. Similarly, Fool behaves like an incautious, carefree child. In the reversed position, the card can represent recklessness or a disregard obvious dangers, which is what leads to the eponymous vampire's downfall.
- He is seen playing a bongo with the others in "Vamps About"
- Jake describes him looking as if "a baby snake was a baby baby".
- The Fool had both his fangs when he was revived, but the Vampire King ripped it out of his mouth.
- He is the only vampire not to be encountered by Finn and Bonnibel, as well as the only vampire to stay with the Vampire King.