Item from Percy Jackson by Rick Riordan
Jason's shape-shifting weapon — a golden coin that becomes a gladius on one flip and a pilum (javelin) on the other. Pure Roman engineering.
Ivlivs is the most Roman weapon in the series — practical, binary, and designed for a soldier who needs to switch between close combat and ranged attack in the space of a heartbeat. A golden coin stamped with Julius Caesar's profile on one side and a battle axe on the other — flip it and it transforms into either a golden gladius for close-quarters swordwork or a pilum javelin for ranged combat, depending on which side lands up. Made of Imperial gold, the Roman equivalent of Celestial bronze, equally deadly to monsters and divine beings. Jason carried it throughout Heroes of Olympus, and it served as a symbol of his Roman identity.
A golden coin stamped with an image of Julius Caesar on one side and an axe on the other. Flip it and it transforms into either a golden gladius (short sword) or a pilum (throwing javelin), depending on which side lands up.
Also known as: Ivlivs, Jason's coin