Petsuchos' Necklace

"The necklace is enchanted. Any reptile that wears it turns into the next petsuchos, the Son of Sobek."

- Carter Kane to Percy Jackson

The petsuchos' necklace was a magical item sacred to Sobek, the Egyptian god of crocodiles. It bears the god's name in hieroglyphs, and has the power to transform a regular crocodile into a larger, more monstrous version of itself.

Description
The petsuchos' necklace was an elaborate collar of gold chains and precious stones, said to be enough to "buy a private island". Sobek's name was inscribed upon it in the form of hieroglyphs, the letter "K" being the clasp.

History
During ancient times, the petsuchos' necklace was worn by a crocodile worshipped in Sobek's temple as a living god. It was later created by the magician Setne by experimenting with Greek and Egyptian magic using the Book of Thoth. He placed it on a baby crocodile, which then proceeded to terrorize Long Island and eat a pegasus from Camp Half-Blood.

The Son of Sobek
The rampaging petsuchos is tracked down by Percy Jackson and Carter Kane to a swamp near Montauk Highway. The two team up to defeat the monster, but come to realize that their attacks have no affect on the petsuchos. Carter recognizes Sobek's name on the petsuchos' necklace, and tells Percy that they need to remove it in order to stop the monster, which has since moved onto a nearby neighborhood.

As Carter battles the petsuchos to keep it occupied, Percy works on removing the necklace. He unsuccessfully tries cutting it with Riptide, but the necklace proves to be resilient to the sword. Carter notices the necklace's clasp, and creates a shabti hippopotamus to draw the petsucho's attention. While Percy conjures a hurricane, Carter transforms into a falcon and flies over to the petsuchos, reverting to human form and grabbing hold of the necklace. He hits several hieroglyphs on the necklace, before hitting the one representing the letter "K". This causes several pounds of gold and gems to spill on Carter. The mound disappears, leaving Carter with the necklace and the baby crocodile that was the petsuchos. He quickly flees the scene with Percy when the police arrives.

The two grab cheeseburgers at a diner, discussing who could possibly have put the petsuchos' necklace on the baby crocodile. Deciding to part without learning about each other's respective worlds, Carter takes the petsuchos' necklace and the baby crocodile with him to Brooklyn House.

Abilities
As the petsuchos' necklace is endowed with the power of Sobek himself, it can transform any reptile into an unstoppable monster that can withstand the joint attacks of both a demigod and magician. This is notable, considering that Percy and Carter are recognized as being among the most powerful of their kind.

The petsuchos' necklace also seems to grant its wearer near invulnerability, as only removing it is key to defeating the monster. Any wounds inflicted will be healed at an accelerated rate.