Sid Genul of the Deep

First Strike, Hexproof
Merfolk creatures you control cannot be the
target of spells or abilities that cause them to
become exiled.
At the start of your combat phase, select one of
the following abilities:
•Deal 8 damage to one target creature or planeswalker.
•3 creatures you control gain Frist Strike and
Hexproof until the end of your turn.