The code is different for everyone. You should begin at the Volcano and follow each of the instructions carefully, and in order, to complete the Super Moshi Mission.
You have to be a (paid) Moshi Monsters Member.
But here is how to find out what your code is.
- Go to the For Rent building on Sludge Street to start.
- Go to Sludge Street and click on the man that is fishing. He should give you a letter.
- Go to Main Street and click on the man that is reading a book. He should give you another letter.
- Go back to Sludge Street and click on the man listening to music. He should give you another letter.
- Go back to the For Rent building on Sludge Street and find the piece of paper to enter the code.