This is a project I have been working on that allows you to make your own My Singing Monsters island, there are instructions if you remix it basically all you have to change is the example monster and eggs, duplicate the example monster (dont edit the original one save it for last), If you look inside the example monster and eggs code at the top you should see some notes that is the code you need to edit, follow what the notes say and it should be easy, elements can be anything as long as they are reucurring throughout your monsters If you decide to give your monster an egg make sure to name the egg costume the exact name of your monster otherwise it won't work, and copy the costume of the example egg as a base, or else the egg might look wrong in the breeding station or hatchery
NOTE: This game is in progress and will recieve future updates UPDATE 1.1 songs can now have 5 parts letting you have an actual song, again please make your own islands with this and i will try to publish my own soon.