Tefnut, Goddess of Water

Renewed Faith - As long as you control 3 or more Merfolk, Tefnut, Goddess of Water has Hexproof and "Other blue and green creatures you control get +2/+2 and have Islandwalk and Hexproof"
Islandwalk
{1}{u}{g}: Put a +1/+1 counter on target creature you control. If that creature is a Merfolk draw a card.