Poptropica Creators are the creators of the online game Poptropica - developers, artists, and writers - along with any other staff member on the Poptropica team. The term "Creator" stems from the "Poptropica Creators' Blog", which most people refer to as the Creators Blog, thus the name. A complete list of all the staff on the Poptropica team has never been fully achieved, as most Creators remain secretive about their work. There are a handful, however, who do openly interact with fans. There are apparently 31 staff members belonging to the team, according to this tweet. A list of creators can be found here.
Most Creators who have a public status usually are assigned aliases from the game - for example Mitch Krypta's Poptropica alias is Hades, god of the underworld. These aliases are used on the Creator's Blog as well as for campaigns and other miscellaneous appearances (sometimes inside the game).
Creator's usually also have special accounts with their character's attire and custome name on them. These Poptropicans are some of the few custom named accounts - for instance, Jordan Leary has an account with Dr. Hare as the Poptropican's name. These accounts can be friended and the custom names show up on Friends. This is rumored to be because of a filter that prevents names outside of the set Creator names. Skilled coders who may change their names still cannot make their custom names show up on Friends.
Also, the only account to have 3 prefixes, Vlad The Viking, is owned presumably by a Poptropica creator. His actual account is unknown but the name can be seen in a video showcasing the Multiverse feature.