you do.
Today!
You don't!
There is no key card in skullduggery island.
it is the skull with the cavity on it.
you have to get canon powder and light the canon the powder is in the shop on that island
On each island once you complete the missions for them.
Its simple, you just have to look up the cheats and do it yourself!
If its on mythology island, get Hercules to move it for you. press the skull on the mirror and Herc will move it for you.
It is located at the top of the Petey's pirate pub.
3 times
You don't climb it. You have to find the cannon starting kit and explosives barrel on that island and push the TNT under the yellow tooth of the skull, fire the nearbye cannon and the map piece will be where the tooth was.
Yes in time tangled island there's a Viking suit and glasses and on legendary swords there a skull mask