Hamustar is or was a moderator and QA Tester for Club Penguin. It is currently unknown whether she left her job working on the game or not. She was also known to post on the Miniclip Club Penguin Forums, and she was also a moderator on them. 
Not much is known about her, other than that she became a moderator because her husband was working as a programmer, and he told her about moderators, so she decided to apply to become one.
She has helped with ideas for new features and parties.
She is or was a QA Tester, which means that she organized and tracked all the features that have to go up on the website to make sure all the pieces are handed over for launch.
She likes to play lots of video games and board games, and watch movies and TV shows with her friends. She also sews plush toys for fun.
Strangely, if you type 'Hamustar' in the Buddy List it will say there is no such penguin.