Sharkigators, also referred to as sewer sharks or pool sharks are enemies in Ratchet & Clank, the 2016 re-imagined game, Going Commando, Up Your Arsenal, and Size Matters. They are hostile fish-like creatures that swim in the waters and will swallow Ratchet and Clank if they stray too close to them.
Ratchet & Clank
Sharkigators first appeared in Blackwater City, Rilgar, in the waters surrounding the ship. If Ratchet and Clank dived into the waters, a sharkigator would eat them. When exploring Blackwater City's sewers during "Locate Captain Qwark", the two were often required to clear several pools of sharkigators, by using the Hydrodisplacer to drain the water and then jumping in to kill them before refilling it to swim through safely. Sharkigators had a similar role in Qwark's headquarters, Umbris, during "Survive Qwark's gauntlet".
In Qwark's version of events, sharkigators were first seen in Aleero City, Kerwan, transported by a grav-train headed to the Hall of Heroes in "Ride the train to the Hall of Heroes", though they posed no threat. They were later encountered in Blackwater City on Rilgar, where they patrolled the waters, and Ratchet had to defeat several sharkigators during "Search the sewers" to defeat the sharkigators. Later, sharkigators were encountered in Jowai Resort, Pokitaru. Unlike from Size Matters, they instead would eat Ratchet if he swam too far away from the resort.
Sharkigators appeared in Canal City, Notak patrolling the water. Ratchet was unable to defeat them, but inside the factory, he had to use the Thermanator to freeze water and prevent them from eating him. Sharkigators also patrolled the waters on Dobbo and Todano.
Up Your Arsenal
Sharkigators were located in Jowai Resort, Pokitaru, and would eat Ratchet if he entered the waters. They were later seen during Ratchet's Dreamtime sequence.
Secret Agent Clank
Sharkigators could be found swimming behind the glass walls of the Prison Showers.
Sharkigators are short sharks with sharp teeth and yellow eyes. They come in two variants: the sharkigators on Umbris, Rilgar, and in the factory on Notak have a green color, while the sharks in the ocean on Notak, Dobbo, Todano, and Daxx have an orange color. On Pokitaru in Size Matters, the orange sharks have green pupiled eyes rather than glowing yellow eyes.
Sharkigators inhabit either oceans or pools of water and eat Ratchet if he swims too far from land. When sharkigators are found lurking in the water on a planet, signified by their visible fin, this means the water should be avoided. Sharkigators eat Ratchet within moments after he ends up in the water, giving him a very brief amount of time to exit.
In Ratchet & Clank, when found in pools of water, if the water is drained with the Hydrodisplacer, they will then flop around on the ground and can easily be defeated with an OmniWrench. In Going Commando, in a pool of water, the Thermanator should be used to freeze the water and prevent them from killing Ratchet.
In the re-imagined release of Ratchet & Clank, sharkigators appear in the outskirts of Jowai Resort on Pokitaru, and will bite Ratchet if he swims too far out from land.
Behind the scenes
Sharkigators bear many similarities in appearance and behavior with the lurker shark from Jak and Daxter: The Precursor Legacy, as both sharks patrol the waters as a way to keep the player from hitting level borders.
Insomniac wanted to remove the sharkigator (by designing challenges in which it was not needed) in every Ratchet & Clank game, but failed, as they never found a better way to kill Ratchet if he enters water that the player should not access.