Vanessa the Sea Witch

At the start of each opponents upkeep, you may
pay {1}{b}{b}. If you do, put a +1/+1 counter on
target creature that player controls and goad it.
That player then sacrifice a creature without a
counter on it. Create a 2/2 black and blue
Merfolk creature token.
{u}{b}, {t}: Other merfolk creatures you control
gets +X/+X until end of turn, where X is the
number of merfolks you control.