Animate Dead

Enchant creature card in a graveyard
When Animate Dead enters the battlefield, if it's on the battlefield, it loses "enchant creature card in a graveyard" and gains "enchant creature put onto the battlefield with Animate Dead." Return enchanted creature card to the battlefield under your control and attach Animate Dead to it. When Animate Dead leaves the battlefield, that creature's controller sacrifices it.
Enchanted creature gets -1/-0.

Avacyn, Angel of Hope

Flying, vigilance, indestructible
Other permanents you control have indestructible.

Marsh Flats

{T}, Pay 1 life, Sacrifice Marsh Flats: Search your library for a Plains or Swamp card, put it onto the battlefield, then shuffle.

Stitcher's Supplier

When Stitcher's Supplier enters the battlefield or dies, mill three cards.

Swamp

Iona, Shield of Emeria

Flying
As Iona, Shield of Emeria enters the battlefield, choose a color.
Your opponents can't cast spells of the chosen color.

Putrid Imp

Discard a card: Putrid Imp gains flying until end of turn.
Threshold — As long as seven or more cards are in your graveyard, Putrid Imp gets +1/+1 and can't block.

Dark Ritual

Reanimate

Put target creature card from a graveyard onto the battlefield under your control. You lose life equal to its mana value.

Elesh Norn, Grand Cenobite

Vigilance
Other creatures you control get +2/+2.
Creatures your opponents control get -2/-2.

Entomb

Search your library for a card, put that card into your graveyard, then shuffle.