Fluffy the Fish (a.k.a. Yellow Fish) were small yellow fish who were also recurring characters that appeared in games, missions, rooms, and even on the main currency, the coin, throughout Club Penguin.
Fluffy the Fish was a game for Club Penguin's Beta Team game testers. It was a fun mini-game where the player controlled a Fluffy to eat the smaller fish, thus growing in size after eating so many. The player could use the arrow keys and mouse.
In the back of the first Penguin Style in an advertisement. The ad read: HAVE YOU SEEN ME? Lost: One fish. Answers to the name 'Fluffy'. If found, please return to Zippo Penguin at 2993 West Iceberg Lane. The advertisement was only a joke flier.
Sabre-tooth Fluffies pop up out of the ground as obstacles in the Sled Racer app.
In a picture on a wall in the Lighthouse. Its name was under this picture as well.
According to the first Penguin Style catalog, Fluffy belonged to Zippo the Penguin. Fluffy's appearance in the Penguin Style catalog was also his first official appearance on Club Penguin Island as Fluffy the Fish. When asked, rsnail said that Fluffy is "everywhere" and that it might be connected with an unfinished mission. (also the name of a puffle in the comics)
In the Beta Team's Club Penguin page, there is a game called Fluffy the Fish. However, this has been updated to Fluffy the Fish 2.0.
In the Club Penguin: Elite Penguin Force, three fish appear in different sizes, having to use Mini Fluffy as bait for the Mega Fluffy, but in the Club penguin computer game, they are all the same size.