The combo is 312.
There are no cheat codes on Poptropica. (see the related question)
do you mean skullduggery??
youtube
dragon cove
skullduggery island!
You don't!
5128904
you can get one on skullduggery island
solve the mystery
a map piece
under the bridge on skullduggery
Probably the most difficult island on poptropica is the latest one, Skullduggery. However, it is a matter of opinion. Besides Skullduggery , thay are pretty much the same.=)