Swamp

Restless Cottage

Restless Cottage enters tapped.
{T}: Add {B} or {G}.
{2}{B}{G}: Restless Cottage becomes a 4/4 black and green Horror creature until end of turn. It's still a land.
Whenever Restless Cottage attacks, create a Food token and exile up to one target card from a graveyard.

Wake Thrasher

Whenever a permanent you control becomes untapped, Wake Thrasher gets +1/+1 until end of turn.

Augury Raven

Flying
Foretell {1}{U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Merfolk Trickster

Flash
When Merfolk Trickster enters, tap target creature an opponent controls. It loses all abilities until end of turn.

Lord Skitter, Sewer King

Whenever another Rat you control enters, exile up to one target card from an opponent's graveyard.
At the beginning of combat on your turn, create a 1/1 black Rat creature token with "This creature can't block."

Yavimaya Coast

{T}: Add {C}.
{T}: Add {G} or {U}. Yavimaya Coast deals 1 damage to you.

Butcher's Glee

Target creature gets +3/+0 and gains lifelink until end of turn. Regenerate it. (Damage dealt by a creature with lifelink also causes its controller to gain that much life.)

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Bitterblossom

At the beginning of your upkeep, you lose 1 life and create a 1/1 black Faerie Rogue creature token with flying.

Inkfathom Infiltrator

Inkfathom Infiltrator can't block and can't be blocked.

Piper of the Swarm

Rats you control have menace.
{1}{B}, {T}: Create a 1/1 black Rat creature token.
{2}{B}{B}, {T}, Sacrifice three Rats: Gain control of target creature.

Petty Theft

Return target nonland permanent an opponent controls to its owner's hand.

Brazen Borrower

Flash
Flying
Brazen Borrower can block only creatures with flying.

Brazen Borrower // Petty Theft

Merfolk Sovereign

Other Merfolk creatures you control get +1/+1.
{T}: Target Merfolk creature can't be blocked this turn.

Island

Umara Skyfalls

Umara Skyfalls enters tapped.
{T}: Add {U}.

Umara Wizard

Whenever you cast an instant, sorcery, or Wizard spell, Umara Wizard gains flying until end of turn.

Umara Wizard // Umara Skyfalls

Deep Analysis

Target player draws two cards.
Flashback—{1}{U}, Pay 3 life. (You may cast this card from your graveyard for its flashback cost. Then exile it.)