The Giant Crab (nicknamed Mr. Crabby by Percy Jackson) is a creature which Percy encountered and defeated on the Princess Andromeda.


In Greek mythology, Karkinos came to the Hydra's aid sent by Hera. It was defeated and kicked into the stars by Hercules with him only using his bare hands. It is also said that Hercules crushed a giant crab under his foot.

Afterwards, Karkinos was honored as the constellation Cancer.

Percy Jackson and the Olympians

The Last Olympian

Hey, crabby. I'm just gonna scoot around you so-

Percy Jackson to Karkinos, in The Last Olympian

While Percy Jackson was on board Princess Andromeda with Charles Beckendorf on their mission to blow up the ship, Percy had to distract the monsters so Beckendorf had time to plant the bombs. Percy met Karkinos on the fountain in the middle of the courtyard, in the promenade. While fighting it, Percy defeated Karkinos by making the ground slick with water, and then sliding underneath him to stab the Crab in its weak spot, which was the belly, with Riptide. He did this by remembering what Paul Blofis had taught him during their crabbing trip. Karkinos dissolved, leaving behind its empty shell as a spoil of war.


I'm not talking "giant" like $7.99 all-you-can-eat Alaskan king crab. I'm talking giant like bigger than the fountain. The monster rose ten feet out of the water. Its shell was mottled blue and green, its pincers longer than my body.

Percy on Karkinos's appearance, in The Last Olympian

Karkinos was bigger than a large water fountain, precisely ten feet tall, its shell mottled blue and green. It had pincers longer than Percy Jackson's body and black eyes full of intelligence and hate. It had a terrible smell, similar to that of garbage. It constantly foamed at the mouth when Percy encountered it.


  • It has hard, powerful pincers longer than a man's body.
  • It possess amazing speed.
  • It has a near impenetrable shell.
  • It can launch a spray of pressurized water.
  • Its original form might have been the giant crab Karkinos.
Species: Arai | Blemmyae | Basilisks | Centaur | Cyclopes | Dragon | Drakon | Empousai | Fire-Breathing Horse | Gegeines | Gemini | Ghoul | Giants | Gorgons | Harpies | Hekatonkheires | Hippalektryons | Hippocampi | Hyperborean Giants | Ichthyocentaur | Karpoi | Katoblepones | Keres | Laistrygonian Giants | Lycanthrope | Makhai | Merpeople | Myrmekes | Nikai | Nymphs | Pegasus | Satyrs | Stymphalian Birds | Telekhines | Scythian Dracanae | Sirens | Unicorns | Venti | Yales
Friendly Monsters: Argus | Blackjack | Briares | Chiron | Cottus | Don | Ella | Festus | Gleeson Hedge | Gray | Grover Underwood | Guido | Gyges | Lysas | Mellie | Mrs. O'Leary | Ophiotaurus | Peaches | Peleus | Porkpie | Rainbow | Scipio | Tyson | Tempest | Sssssarah
Enemy Monsters: Antaeus | Agrius and Oreius | Arachne | Cacus | Carthaginian Serpent | Charybdis and Scylla | Chimera | Chrysaor | Clazmonian Sow | Colchis Bulls | Echidna | Euryale | Geryon | Joe Bob | Kampê | Kekrops | Ladon | Lamia | Manticore | Medusa | Minotaur | Nanette | Nemean Lion | Polyphemus | Python | Sphinx | Stheno | Typhon | Trojan Sea Monster
Neutral Monsters: Carnivorous Sheep | Cerberus | Erymanthian Boar | Gray Sisters | Flesh-Eating Horse | Furies | Gryphon | Orthus | Skolopendra | Sybaris