Siren Stormtamer

Flying
{U}, Sacrifice Siren Stormtamer: Counter target spell or ability that targets you or a creature you control.

An Offer You Can't Refuse

Counter target noncreature spell. Its controller creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Sea-Dasher Octopus

Mutate {1}{U} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Flash
Whenever this creature deals combat damage to a player, draw a card.

Skullwinder

Deathtouch
When Skullwinder enters, return target card from your graveyard to your hand, then choose an opponent. That player returns a card from their graveyard to their hand.

Hypnotic Siren

Bestow {5}{U}{U} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Flying
You control enchanted creature.
Enchanted creature gets +1/+1 and has flying.

Vineglimmer Snarl

As Vineglimmer Snarl enters, you may reveal a Forest or Island card from your hand. If you don't, Vineglimmer Snarl enters tapped.
{T}: Add {G} or {U}.

Verdant Embrace

Enchant creature
Enchanted creature gets +3/+3 and has "At the beginning of each upkeep, create a 1/1 green Saproling creature token."

Eidolon of Blossoms

Constellation — Whenever Eidolon of Blossoms or another enchantment you control enters, draw a card.

Charge Through

Target creature gains trample until end of turn.
Draw a card.

Fyndhorn Elves

Fated Infatuation

Create a token that's a copy of target creature you control. If it's your turn, scry 2.

Forest

Shielding Plax

({G/U} can be paid with either {G} or {U}.)
Enchant creature
When Shielding Plax enters, draw a card.
Enchanted creature can't be the target of spells or abilities your opponents control.

Gemrazer

Mutate {1}{G}{G} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Reach, trample
Whenever this creature mutates, destroy target artifact or enchantment an opponent controls.

Keen Sense

Enchant creature
Whenever enchanted creature deals damage to an opponent, you may draw a card.

Arbor Elf

Dreamtail Heron

Mutate {3}{U} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Flying
Whenever this creature mutates, draw a card.

Mark of Sakiko

Enchant creature
Enchanted creature has "Whenever this creature deals combat damage to a player, add that much {G}. Until end of turn, you don't lose this mana as steps and phases end."

Ghostly Touch

Enchant creature
Enchanted creature has "Whenever this creature attacks, you may tap or untap target permanent."

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Followed Footsteps

Enchant creature
At the beginning of your upkeep, create a token that's a copy of enchanted creature.

Ivy, Gleeful Spellthief

Flying
Whenever a player casts a spell that targets only a single creature other than Ivy, Gleeful Spellthief, you may copy that spell. The copy targets Ivy. (A copy of an Aura spell becomes a token.)

Sixth Sense

Enchant creature
Enchanted creature has "Whenever this creature deals combat damage to a player, you may draw a card."

Joraga Treespeaker

Level up {1}{G} ({1}{G}: Put a level counter on this. Level up only as a sorcery.)
LEVEL 1-4
1/2
{T}: Add {G}{G}.
LEVEL 5+
1/4
Elves you control have "{T}: Add {G}{G}."

Lofty Denial

Counter target spell unless its controller pays {1}. If you control a creature with flying, counter that spell unless its controller pays {4} instead.

Invisible Stalker

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
Invisible Stalker can't be blocked.

One with Nature

Enchant creature
Whenever enchanted creature deals combat damage to a player, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Negate

Cerulean Wisps

Target creature becomes blue until end of turn. Untap that creature.
Draw a card.

Cloud of Faeries

Flying
When Cloud of Faeries enters, untap up to two lands.
Cycling {2} ({2}, Discard this card: Draw a card.)

Twinning Staff

If you would copy a spell one or more times, instead copy it that many times plus an additional time. You may choose new targets for the additional copy.
{7}, {T}: Copy target instant or sorcery spell you control. You may choose new targets for the copy.

Errant, Street Artist

Flash
Defender, haste
{1}{U}, {T}: Copy target spell you control that wasn't cast. You may choose new targets for the copy.

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.

Prevent all combat damage that would be dealt this turn.

Curse of the Swine

Exile X target creatures. For each creature exiled this way, its controller creates a 2/2 green Boar creature token.

Wild Growth

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional {G}.

Nature's Claim

Destroy target artifact or enchantment. Its controller gains 4 life.

Croaking Counterpart

Create a token that's a copy of target non-Frog creature, except it's a 1/1 green Frog.
Flashback {3}{G}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Leap

Target creature gains flying until end of turn.
Draw a card.

Corrupted Conscience

Enchant creature
You control enchanted creature.
Enchanted creature has infect. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Endless Evil

Enchant creature you control
At the beginning of your upkeep, create a token that's a copy of enchanted creature, except the token is 1/1.
When enchanted creature dies, if that creature was a Horror, return Endless Evil to its owner's hand.

Ancestral Mask

Enchant creature
Enchanted creature gets +2/+2 for each other enchantment on the battlefield.

Overgrowth

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional {G}{G}.

Biovisionary

At the beginning of the end step, if you control four or more creatures named Biovisionary, you win the game.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Island

Setessan Champion

Constellation — Whenever an enchantment you control enters, put a +1/+1 counter on Setessan Champion and draw a card.

Auspicious Starrix

Mutate {5}{G} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Whenever this creature mutates, exile cards from the top of your library until you exile X permanent cards, where X is the number of times this creature has mutated. Put those permanent cards onto the battlefield.

Snake Umbra

Enchant creature
Enchanted creature gets +1/+1 and has "Whenever this creature deals damage to an opponent, you may draw a card."
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Precursor Golem

When Precursor Golem enters, create two 3/3 colorless Golem artifact creature tokens.
Whenever a player casts an instant or sorcery spell that targets only a single Golem, that player copies that spell for each other Golem that spell could target. Each copy targets a different one of those Golems.

Sisay's Ingenuity

Enchant creature
When Sisay's Ingenuity enters, draw a card.
Enchanted creature has "{2}{U}: Target creature becomes the color of your choice until end of turn."

Frog Tongue

Enchant creature
When Frog Tongue enters, draw a card.
Enchanted creature has reach. (It can block creatures with flying.)

Migratory Greathorn

Mutate {2}{G} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Whenever this creature mutates, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Wolfwillow Haven

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional {G}.
{4}{G}, Sacrifice Wolfwillow Haven: Create a 2/2 green Wolf creature token. Activate only during your turn.

Slip Out the Back

Put a +1/+1 counter on target creature. It phases out. (Treat it and anything attached to it as though they don't exist until its controller's next turn.)

Fertile Ground

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional one mana of any color.

Bear Umbra

Enchant creature
Enchanted creature gets +2/+2 and has "Whenever this creature attacks, untap all lands you control."
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Abduction

Enchant creature
When Abduction enters, untap enchanted creature.
You control enchanted creature.
When enchanted creature dies, return that card to the battlefield under its owner's control.

Counterspell

Spellwild Ouphe

Spells that target Spellwild Ouphe cost {2} less to cast.

Quasiduplicate

Create a token that's a copy of target creature you control.
Jump-start (You may cast this card from your graveyard by discarding a card in addition to paying its other costs. Then exile this card.)

Stormchaser Drake

Flying
Whenever Stormchaser Drake becomes the target of a spell you control, draw a card.

Kodama's Reach

Slip Through Space

Devoid (This card has no color.)
Target creature can't be blocked this turn.
Draw a card.

Curiosity

Elvish Mystic

Spellskite

{U/P}: Change a target of target spell or ability to Spellskite. ({U/P} can be paid with either {U} or 2 life.)

Rite of Replication

Kicker {5} (You may pay an additional {5} as you cast this spell.)
Create a token that's a copy of target creature. If this spell was kicked, create five of those tokens instead.

Replicate

Create a token that's a copy of target creature you control.

Repudiate

Counter target activated or triggered ability. (Mana abilities can't be targeted.)