Sigarda, Host of Herons

Flying, hexproof
Spells and abilities your opponents control can't cause you to sacrifice permanents.

Karametra, God of Harvests

Indestructible
As long as your devotion to green and white is less than seven, Karametra isn't a creature.
Whenever you cast a creature spell, you may search your library for a Forest or Plains card, put it onto the battlefield tapped, then shuffle.

Tajuru Preserver

Spells and abilities your opponents control can't cause you to sacrifice permanents.