Jewel, Tidal Thief

Hexproof, Skulk (They can't be blocked by
creatures with greater power.)
Islandwalk
Other Merfolk you control have Skulk.
Whenever a Pirate you control deals combat
damage to a player, create a Treasure token.
(It's an artifact with "{t}: Sacrifice this artifact:
Add one mana of any color.")
{2}{w}{u}: Other creatures you control gain
Hexproof until end of turn.