Klunk

Klunk was the evil counterpart of Clank whose homeworld was planet Mariona. He was created by Dr. Nefarious to be a spy replacing Clank. His name was given to him by Nefarious as a joke in Metropolis. Compared to Clank, he was as same looking and weighed as possible so Ratchet couldn't see any difference between them. Klunk had red eyes instead of green like Clank, but Klunk could turn them green which he did to fool Ratchet in Ratchet & Clank: Up Your Arsenal.

Ratchet & Clank: Up Your Arsenal
In Ratchet & Clank: Up Your Arsenal, Klunk replaced Clank after his completion of an episode of Secret Agent Clank at Holostar Studios. As the true Clank refused to assist Dr. Nefarious, he was imprisoned and Klunk was built to take his place. Klunk continued posing as Clank throughout a large portion of the remaining game, with Ratchet only extremely slowly becoming aware that something was amiss. Klunk's true identity was only revealed at the end of the Metropolis level, at which point he transformed into his Giant Klunk form and dueled Ratchet atop a pair of moving Hover Trains. Klunk was seemingly destroyed and the real Clank returned.

Ratchet & Clank: Size Matters
In Size Matters, Ratchet was trapped in a dream sequence where he attempted to follow a red-eyed ghost Clank, who continued to tell him "it is safe inside this door". This Clank, in addition to being able to float and remove his head, had a color scheme and appearance bearing a strong resemblance to Klunk. He also appeared in an even more massive Giant Clank form, though all of his attacks were instead made out of butterflies. Interestingly, the "Friends Don't Hurt Friends" skill point could be obtained for not taking damage during the 'fight' with Clank, and his color scheme was actually that of Giant Clank.

Secret Agent Clank
In Secret Agent Clank, Klunk was revealed to have survived his defeat in Up Your Arsenal. He had spent the next few months making hightech toilet seats but quit after the defeat of Otto Destruct. He was the mastermind in Secret Agent Clank and he was also behind the theft of the Eye of Infinity and framed Ratchet by using a mind control device on him. He had controlled The Kingpin the whole time and created a laser that could blow up every planet in the Solana galaxy unless Clank stopped it. At the end, Klunk became a vacuum cleaner for Clank's apartment, prompting Clank to humorously state that it 'sucks' to be him. However, he blinked and his eyes glowed, hinting that he would return, possibly in Ratchet & Clank Future: A Crack in Time since his creator Dr. Nefarious would be back.

Appearence
Klunk was easily discernable from the true Clank by his eerily red eyes and sinister laugh, though he could hide both of these qualities in order to pose as the original. Ratchet felt really stupid when he failed to interpret these strange behaviors early on. While transformed into Giant Klunk, he also had a darker color scheme. In Secret Agent Clank, he wore a golden suit and a goatee.

Personality
Klunk had more evil and less careful personality than Clank. He also didn't seem to like having orders from anyone. He seemed to like giving orders by himself as he gathered an army after the defeat of Otto Destruct. He cared little for the welfare of others, as evidenced when he coldly refused to stay on Dr. Nefarious' star cruiser even while Captain Qwark was still on board. It was also not above himself to swear.

Powers and Abilities
Klunk was fitted with Heli-Pack, Thruster-Pack and Hydro-Pack upgrades like Clank. During the boss fight against him in Up Your Arsenal, Klunk exhibited an ability to turn into an Ultra-Mech like Clank, but without using an Ultra-Mech pad. This 'Giant Klunk' was a stronger and more well armored version of Giant Clank. He possessed all of the attacks ever used by Giant Clank at a higher level of power, in addition to a small number that were not unusable by the original. He fired missiles, hovered with jet boosters, and hurled energy bombs, however his stupidity let him down as he followed the same pattern of attacks against Ratchet throughout the fight, making him extremely predictable.

Trivia

 * It was possible (though rare) for Giant Klunk to mis-time his first movement and fall off the train roughly five seconds into the fight. If this happened, the game must be reset, as this did not actually kill him and thus does not trigger the next cutscene.
 * While fighting Dr. Nefarious at the Biobliterator launch site, players commonly hid behind various pieces of scrap and debris. One of them was a blackened, Clank/Klunk-like robot body. This implied that Nefarious made several attempts at creating a workable Klunk and dealt harshly with the failures.
 * Klunk had apparently taken after Nefarious' dislike of organic life forms, as he called them "squishes" in Secret Agent Clank as Nefarious did in Up Your Arsenal.
 * Klunk's homeworld, Mariona, could be seen by watching him with the Holo-Monocle in Secret Agent Clank.
 * At Metalis in Junkyard LXIV, if you look across left while at the door of the secret area, you would see in the pool what appeared to be a Giant Klunk head.
 * It was possible that Klunk would return in A Crack in Time due to the fact that Dr. Nefarious, his creator, would be in there, but this is still unknown.
 * Klunk (in his Gold tuxedo) is a Skin in Secret Agent Clank.
 * Clank has a small beard in the same game.

Appearances

 * Ratchet & Clank: Up Your Arsenal
 * Secret Agent Clank
 * Ratchet & Clank: Size Matters (cameo)