Island Sinker

Hexproof, islandwalk
Island Sinker can't attack unless defending player controls an Island. When you control no Islands, sacrifice Island Sinker.
Whenever Island Sinker enters the battlefield, you may sacrifice any number of Islands.
Whenever Island Sinker deals combat damage to
an opponent, that opponent sacrifices an Island.
Whenever a player sacrifices an Island, put a +1/+1 counter on Island Sinker.