In Percy Jackson, it's spelled "Kampê", but it's also spelled with a "C", Campe. Wikipedia gives this as its overview:
In Greek mythology, Campe or Kampe (/ˈkæmpiː/; Greek: Κάμπη) was a female monster. She was the guard, in Tartarus, of the Cyclopes and Hecatoncheires, whom Uranus had imprisoned there. When it was prophesied to Zeus that he would be victorious in the Titanomachy—the great war against the Titans—with the help of Campe's prisoners, he killed Campe, freeing the Cyclopes and Hecatoncheires, who then helped Zeus defeat Cronus.
Later on, Wikipedia has this description:
According to Nonnus, Zeus, with his thunderbolt, destroyed:
highheaded Campe ... for all the many crooked shapes of her whole body. A thousand crawlers from her viperish feet, spitting poison afar, were fanning Enyo to a flame, a mass of misshapen coils. Round her neck flowered fifty various heads of wild beasts : some roared with lion's heads like the grim face of the riddling Sphinx; others were spluttering foam from the tusks of wild boars; her countenance was the very image of Scylla with a marshalled regiment of thronging dog's heads. Doubleshaped, she appeared a woman to the middle of her body, with clusters of poison-spitting serpents for hair. Her giant form, from the chest to the parting-point of the thighs, was covered all over with a bastard shape of hard sea-monsters' scales. The claws of her wide-scattering hands were curved like a crooktalon sickle. From her neck over her terrible shoulders, with tail raised high over her throat, a scorpion with an icy sting sharp-whetted crawled and coiled upon itself. Such was manifoldshaped Campe as she rose writhing, and flew roaming about earth and air and briny deep, and flapping a couple of dusky wings, rousing tempests and arming gales, that blackwinged nymphe of Tartaros: from her eyelids a flickering flame belched out far-travelling sparks.
..which more or less seems to be how Rick describes her in the books.
