Kerkopes

The Kerkopes (also spelled Cercopes) are two brothers, Passalos and Akmon. They were turned into monkeys by Zeus due to their constant thievery. They are encountered by Leo Valdez and the crew of the Argo II in The House of Hades.

History
In Greek Mythology, the Kerkopes were the children of Oceanus and Theia. Growing up, they were warned by their prophetic mother to beware the "Black Bottomed man." They became thieves, until Heracles caught them trying to steal from him. He tied them to a pole and carried them behind him. They were forced to look at his bottom, which had turned black from sunburn and dirt. So, He was the "Black Bottomed Man." He eventually let them go because they made really funny jokes. Zeus them turned them into monkeys.

The House of Hades
They've set up shop in Bologna, Italy. When the Argo II docks there, they attack the ship and rob it, taking things like an Archimedes Sphere and Piper McLean's dagger, Katoptris. Leo Valdez and Jason Grace chased after them, determined to get their stuff back. At the Fountain of Neptune, they incapacitated Jason by trapping him in a net. Leo chases them to their hide-out and defeats them with a home-made flash-bang grenade. He then got their possessions back and agreed not to kill Passalos and Akmon on the condition that they go to America and disrupt the Romans in order to slow down their attack on Camp Half-Blood. Later in a dream, it is shown that they are being very successful in this goal.