Several characters originating from books based on Club Penguin (such as the "Pick Your Path" books) were given names with less than four characters, such as "Liz", "Kip", "Deb", and "Roy". According to former artist Chris Hendricks, this was done to prevent the writers from potentially copying a real player's penguin name, which were a minimum of four characters long.

Chris Hendricks, a former artist and composer for Club Penguin, was originally against the inclusion of the game's main villain Herbert P. Bear, as he felt that Club Penguin was a game that was meant to be "safe and fun" and thus didn't need a villain. However, during development of the PSA missions, it became apparent that it was becoming difficult to put obstacles in the player's way without some sort of villain behind it. The team member who first pitched the idea of adding a villain to the game initially came up with the idea of there being three polar bears: a boss bear, a skinny vegetarian henchman bear, and a big stupid bear who would lift heavy objects and be endearing and lovable. Some staff, however, felt that this was too many bears, and eventually reached a compromise: take all the best attributes of the three bears, combine them into one bear, and give him a lovable sidekick.

Chris, however, was still concerned about the idea of adding a villain, so to both build up mystery and try to appease him, the story was developed so that the villain wouldn't be revealed until the fifth mission: in the third mission, the only evidence of the villain was white fur. This gave them a potential escape route in case players didn't want a villain in the game, as they could have the fourth mission reveal that the whole thing was a misunderstanding and that a white puffle (which hadn't debuted at that point) was to blame. As it would turn out, fans loved the idea of a villain, so the fourth mission would give a shadowy teaser of the villain, before the full reveal of Herbert P. Bear in the fifth mission. Chris would later admit that he was wrong to not want a villain in the game, as Herbert became one of his favorite characters, and lead to the introduction of other memorable villains (i.e. Tusk and Ultimate Proto-Bot 10000) as well.

There is an unused block button in the game files.