Thing of Darkness and Light

Plains Landfall - Whenever a plains enters the battlefield under your control you may have it
become a 2/2 flying spirit elemental that is still a
land until end of turn. If you do you gain 2 life.
Swamp Landfall - Whenever a swamp enters the battlefield under your control you may have it
become a 2/2 deathtouch zombie elemental that
is still a land until end of turn. If you do target opponent loses 2 life.