Hedron Crab

Landfall — Whenever a land you control enters, target player mills three cards.

Venture Deeper

Target player mills four cards. (Then exile this card. You may cast the creature later from exile.)

Merfolk Secretkeeper

Merfolk Secretkeeper // Venture Deeper

Swamp

Stitcher's Supplier

When Stitcher's Supplier enters or dies, mill three cards. (Put the top three cards of your library into your graveyard.)

Narcomoeba

Flying
When Narcomoeba is put into your graveyard from your library, you may put it onto the battlefield.

Prized Amalgam

Whenever a creature enters, if it entered from your graveyard or you cast it from your graveyard, return Prized Amalgam from your graveyard to the battlefield tapped at the beginning of the next end step.

Creeping Chill

Creeping Chill deals 3 damage to each opponent and you gain 3 life.
When Creeping Chill is put into your graveyard from your library, you may exile it. If you do, Creeping Chill deals 3 damage to each opponent and you gain 3 life.

Evolving Wilds

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Island

Vengevine

Haste
Whenever you cast a spell, if it's the second creature spell you cast this turn, you may return Vengevine from your graveyard to the battlefield.

Otherworldly Gaze

Surveil 3. (Look at the top three cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
Flashback {1}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Terramorphic Expanse

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Wonder

Flying
As long as Wonder is in your graveyard and you control an Island, creatures you control have flying.

Glimpse the Unthinkable

Haunted Dead

When Haunted Dead enters, create a 1/1 white Spirit creature token with flying.
{1}{B}, Discard two cards: Return Haunted Dead from your graveyard to the battlefield tapped.

Gravecrawler

Gravecrawler can't block.
You may cast Gravecrawler from your graveyard as long as you control a Zombie.