Enchant creature Enchanted creature has double strike.

Whenever you clash, tap target creature an opponent controls. If you won, that creature doesn’t untap during its controller’s next untap step. (This ability triggers after the clash ends.)

%W, %T: Harpoon Sniper deals X damage to target attacking or blocking creature, where X is the number of Merfolk you control.

First strikeLifelink (Whenever this creature deals damage, you gain that much life.)

Prevent all combat damage that would be dealt this turn. Clash with an opponent. If you win, creatures that player controls don’t untap during the player’s next untap step. (Each clashing player reveals the top card of his or her library, then puts that card on the top or bottom. A player wins if his or her card had a higher converted mana cost.)

DefenderAt the beginning of combat on your turn, you may clash with an opponent. If you win, Sentry Oak gets +2/+0 and loses defender until end of turn. (Each clashing player reveals the top card of his or her library, then puts that card on the top or bottom. A player wins if his or her card had a higher converted mana cost.)