Four Islands

From the introduction:

The Isle of Massive Crustaceans sees the party square off against a sorcerer-tyrant and his monstrous pets in a tropical setting, near Cesaire in Cube World, near Madagascar in LotFP.
The Isle of the Lava Trolls is a volcanic island-fortress north of Nephilidia or Iceland
The Isle of Fifty Fingers allows the party to take control of a small skirmish force for a mini-wargame in the Peacock Isles/India.
The Isle of the Spawn King places the titular ruler in the center of a ring of horrible mutant slaves bent on making the party join them, on an island deep within Spawn Lake in Broceliande--or in Siberia.