Bad River enters tapped.

, Sacrifice Bad River: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

When this creature dies, return target creature card with mana value 2 or less from your graveyard to the battlefield.

Battle cry (Whenever this creature attacks, each other attacking creature gets +1/+0 until end of turn.)

When Grixis Slavedriver leaves the battlefield, create a 2/2 black Zombie creature token.

Unearth (: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Ward

Other Frogs you control have ward .

When Long River Lurker enters, target creature you control can't be blocked this turn. Whenever that creature deals combat damage this turn, you may exile it. If you do, return it to the battlefield under its owner's control.

, : You gain 1 life. Put a brick counter on Luxa River Shrine.

: You gain 2 life. Activate only if there are three or more brick counters on Luxa River Shrine.

: Regenerate Marang River Skeleton.

Megamorph (You may cast this card face down as a 2/2 creature for . Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)

Whenever Mistford River Turtle attacks, another target attacking non-Human creature can't be blocked this turn.

Whenever another creature you control enters, that creature gets +2/+0 and gains haste until end of turn. (It can attack and this turn.)

Whenever one or more creatures you control attack, each defending player divides all creatures without flying they control into a "left" pile and a "right" pile. Then, for each attacking creature you control, choose "left" or "right." That creature can't be blocked this combat except by creatures with flying and creatures in a pile with the chosen label.

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)

: Regenerate River Boa.

River Delta doesn't untap during your untap step if it has a depletion counter on it.

At the beginning of your upkeep, remove a depletion counter from River Delta.

: Add or . Put a depletion counter on River Delta.

When River Herald Scout enters, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)

Flying

: You gain 2 life and draw a card.

Whenever River Kelpie or another permanent enters from a graveyard, draw a card.

Whenever a player casts a spell from a graveyard, draw a card.

Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

: Add . If you played a land this turn, add instead.

River Sneak can't be blocked.

Whenever another Merfolk you control enters, River Sneak gets +1/+1 until end of turn.

Imprint — Whenever a player casts an instant or sorcery spell from their hand, exile it instead of putting it into a graveyard as it resolves.

At the beginning of your upkeep, if there are four or more cards exiled with River Song's Diary, choose one of them at random. You may cast it without paying its mana cost.

: Add .

If was spent to cast this spell, return up to one target creature to its owner's hand. If was spent to cast this spell, target player reveals their hand, you choose a nonland card from it, then that player discards that card. (Do both if was spent.)

Flying

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Kicker—Sacrifice a land. (You may sacrifice a land in addition to any other costs as you cast this spell.)

Return target nonland permanent to its owner's hand. If this spell was kicked, return another target nonland permanent to its owner's hand.

: Add one mana of any color.

, : Untap another target artifact.

, : Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

, : Target creature can't be blocked this turn.

, , Discard a card: Creatures you control get +1/+1 and gain trample until end of turn.

At the beginning of each end step, if an opponent lost 3 or more life this turn, you may draw a card. (Damage causes loss of life.)

Draw two cards, then you may exile a nonland card from your hand with a number of time counters on it equal to its mana value. Then target opponent does the same. Cards exiled this way that don't have suspend gain suspend.

Time travel. (For each suspended card you own and each permanent you control with a time counter on it, you may add or remove a time counter.)

Choose one —

• Fight the Current — Return target nonland permanent to its owner's hand.

• Find a Crossing — Target creature gets +1/+0 until end of turn and can't be blocked this turn.