Klunk

"How do you like my special creation, Clank? I call him "Klunk". Your dopey friend seems to be quite fond of him. Say, maybe they'll change your show to Secret Agent Klunk!"

- Dr. Nefarious

Klunk is an evil counterpart created by Dr. Nefarious to replace Clank, replacing the original after the completion of Holostar Studios. As the true Clank would not assist Dr. Nefarious, he was imprisoned and Klunk built to take his place. Klunk continues posing as Clank throughout a large portion of the remaining game, with Ratchet only extremely slowly becoming aware that something is amiss. Klunk's true identity is only revealed at the end of the Metropolis level, at which point he transforms into his Giant Klunk form and duels Ratchet atop a pair of moving Hover Trains. Klunk is summarily destroyed and the real Clank returned.

Klunk is easily discernable from the true Clank by his eerily red eyes and wheezing laugh (though he can hide both of these qualities in order to pose as the original). Ratchet felt really stupid when he failed to interpret these strange behaviors earlier. While transformed into Giant Klunk, he also has a darker color scheme.

Giant Klunk
During the boss fight, Klunk exhibits an ability to turn into a giant version of himself. This 'Giant Klunk' is a stronger and more well armored version of Giant Clank. He possesses all of the attacks ever used by Giant Clank at a higher level of power, in addition to a small number that are not usable by the original.

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

Trivia

 * It is 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 happens the game must be reset, as this does not actually kill him and thus does not trigger the next cutscene.
 * Klunk is also the only characer in UYA that curses, almost. During the memorial for the death of Captain Qwark, the President states that Qwark was a brave, noble man. Klunk remarks "What a load of bullsh-" and it cut off by Ratchet.

Appearances

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