Annabeth Chase's Yankees Baseball Cap is a magical item that has the ability to make the person who wears it invisible. As of The Mark of Athena, the magic cap no longer works because of Annabeth's fight with Minerva.


Annabeth's mother, the goddess Athena, gave it to her for her 12th birthday.

The cap is similar to Hades' Helm of Darkness, however it does not have any fear inducing properties. It has had many life-saving uses, quite notably helping Percy escape from the Furies on a bus in The Lightning Thief. Annabeth had used the cap to defeat the Laistrygonians, when they attacked Percy and Tyson in the Sea of monsters. She used it to trick Polyphemus in The Sea of Monsters, escape from Mount Saint Helens in The Battle of the Labyrinth and fight alongside Percy in The Last Olympian. So far, Percy is the only known demigod other than Annabeth who has used this cap.
Annabeth Chase

Annabeth using her cap to turn invisible


In battle, or in any circumstance as a demigod, the hat is very useful. When worn, it makes the user and any item they're holding invisible. That in and of itself would make it very powerful, as its usefulness of stealth is an important and useful factor in battle and ingenuity on Annabeth's part makes it invaluable. It loses its magic in The Mark of Athena, after she fights with her mother.



  • In ancient myths, Athena gave Perseus a helmet that turned him invisible. During the series, Annabeth, a daughter of Athena, has offered to let Percy (Perseus) use it on multiple occasions.
  • In her picture Annabeth is wearing her hat, but in the books, when she has it on she's invisible.
Personal Weapons: Riptide | Annabeth's Knife | Backbiter | Frank's Spear | Hazel's Spatha | Katoptris | Nico's Sword | Thalia's Spear | Aegis | Maimer | Kronos' Scythe | Ivlivs | Master Bolt | Poseidon's Trident | Sword of Hades | Reyna's Spear | Hades' Staff | Juno's Gladius | Annabeth's Sword | Sumarbrander | Gungnir | Gjallar | Mjolnir | Thor's Staff | Khopesh | Mallory's Serrated Knife | Meg's Twin Imperial Gold siccae blades | Caduceus | Apollo's Golden Bow | Artemis' Knives | Ares' Sword | Ares' Shield | Thyrsus | Hecate's Torches | Minotaur's Axe | Leroy's Sword | Tyson's Javelin | Alex’s Garrote Wire
Magical Items: Annabeth's Yankees Cap | Helm of Darkness | Keys of Hades | Flying Chariot | Golden Apple | Apples of Immortality | Greek Fire | Hermes' Multivitamins | Leo's Magical Toolbelt | Nectar and Ambrosia | Pandora's Pithos | Winged Shoes | The Golden Fleece | Stygian Ice Whistle | Serapis' Staff | Magic 8 Ball | Arrow of Dodona | Pig Ball | Mechanical Spider | Angel Statues | Athena Parthenos | Chiron's Wheelchair | Diocletian's Scepter | Flaming Dodgeball | Gleipnir | Poseidon's Pearls | Queen Hippolyta's Belt | Mistletoe Arrow | Frank's Stick | Expand-o-Duck | Caligula’s Sandals | Ran’s Net | Rune Stones | Nábrók
Spoils of War: The Minotaur's Horn | Medusa's Head | Kampê's Scimitars | Nemean Lion's Pelt | Gorgon Blood | Cornucopia | Lydian Drakon Hide | Phineas' Robe and Slippers
Items: Camp Necklace | Chameleon Armor | Daedalus' Laptop | Golden drachma | Denarius | Red Gold | Mark of Athena | The Pax | Video Shield | Wristwatch Shield | Golden Mango | Sibylline Books | Letter of Recommendation
Blessed Metals: Adamantine | Celestial Bronze | Imperial Gold | Stygian Iron | Bone Steel
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