Arctic leviathans are enemies in Going Commando, encountered in the Tundor Wastes on planet Grelbin. They are serpentine creatures with long necks, two large ears akin to wings of a bat, and large, protruding jaws filled with sharp teeth, with two long and thin growths at the end of their chin. They live in the waters beneath the Tundor Wastes, guarding moonstones and attacking foes with their devastating ice breath. Their position is only revealed by portions of cracked ice, from which they emerge when prey draws near. They will sometimes, in the midst of combat, snatch a Y.E.T.I. and eat it.
Though the Y.E.T.I.s had been genetically engineered to hunt down the leviathans, they instead went wild and lived harmoniously with them. Ratchet and Clank encountered the leviathans on Grelbin while searching for moonstones to give to the Mystic, in "Bring Moonstones to Mystic", "Trade moonstones for Hypnomatic Part", and when hunting for moonstones to trade for bolts. A total of 33 leviathans are found on Grelbin, all of which would drop a moonstone when defeated.
Arctic leviathans are among the toughest enemies, being both very durable and capable of dealing a large amount of damage in some distance from their position. Their only attack is their ice breath, which they will charge up and fire at Ratchet. As they live in small ice water pits, they are effectively stationary, but Ratchet will freeze to death if he falls in the water. They are best dealt with using weapons that deal large amounts of damage to a single target in medium to long range, such as the Minirocket Tube, Bouncer, Pulse Rifle, Plasma Coil, or Hoverbomb Gun. Using the Synthenoids, Miniturret Glove, and Shield Charger for back-up is also recommended. Due to their strength and the many Y.E.T.I's that dwell nearby, it is recommended to use an upgraded weapon against either of the foes, if not both, for you will inevitably run out of ammo if relying on unupgraded weapons.
Behind the scenes
If the player brings up the Quick Select while a leviathan is charging its beam, the creature will continue to charge its attack, allowing the energy ball to grow larger and larger until the player resumes the game.