Klutzy, before becoming Herbert P. Bear's accomplice, was once a normal crab in the Club Penguin Island. The two became friends when Klutzy rescued Herbert from drowning. Since that day Klutzy has assisted Herbert in his scheme of destroying penguins, though his impact on events is minimal and Klutzy instead often functions as an omen to Herbert's appearance.
In Secret Mission #6, G tries to question Klutzy, but Klutzy escapes back to Herbert. A Secret Agent followed them to their hideout, but was captured. Then, they both attempt to destroy the Ski Lodge for wood, but the Secret Agent escapes and stops them in time. They fell in a lake, but escaped.
In Secret Mission #8, Klutzy (tried to) help Herbert remove the Boiler after they disrupted life on the island by causing tremors due to digging underground. Thankfully, Klutzy turned out to be more of a hindrance than a help, and delayed Herbert until a Secret Agent cornered them. They narrowly escaped when Herbert accidentally damaged the boiler.
During the Operation: Crustacean, Klutzy gets abducted by an UFO. Herbert wants help from the EPF to find him. In the UFO Herbert finds Klutzy, they steal the UFO's source of power and they leave trough the escape pod.
Klutzy was referenced in Mission #7 as a "funny little guy" by a penguin.
There is also a Series 4 figurine of Herbert and Klutzy.
Klutzy uses many face emotes such as :) and 0_0 while writing.
In one mission, he is seen playing a game while Herbert talks to the agents.
Klutzy probably communicates in morse code the reason why the Crab Translator 3000 blown up during mission 6. However, it may also be because his sharp claws cut through the cage and damaged the microphone.
It has been shown that Klutzy isn't as evil as Herbert.
On the character page for him, it describes Klutzy as cheerful and kind.
His name may come from the fact that he often knocks things over, messes up things, is clumsy, etc.
If you search for his name in the friend list, it will read "Klutzy is a click click clickety click. Try searching for someone else." As his name can be searched, it is possible that he was intended to become a mascot.
In Herbert's Revenge last mission, he will join you when Herbert decided to help you. You could then call him with the puffle whistle.