The 30 Natural Monsters, the 5 Core Seasonals and Jam Boree, Shugabush, and Wubbox can be placed on Gold Island. Only Monsters from the Natural Islands (except Wubbox, Jam Boree and bbli$zard) can be placed on Gold Island.

Aux. Seasonals, Ethereals, Mythicals, Magicals, Werdos, Dipsters, Wublins and Celestials cannot be placed on Gold Island.

If you have a Natural Monster that did not originate from a Natural Island (Plant, Cold, Air, Water and Earth) then you will not be able to place it on Gold Island.