Minsc & Boo, Timeless Heroes

When Minsc & Boo, Timeless Heroes enters and at the beginning of your upkeep, you may create Boo, a legendary 1/1 red Hamster creature token with trample and haste.
+1: Put three +1/+1 counters on up to one target creature with trample or haste.
−2: Sacrifice a creature. When you do, Minsc & Boo, Timeless Heroes deals X damage to any target, where X is that creature's power. If the sacrificed creature was a Hamster, draw X cards.
Minsc & Boo, Timeless Heroes can be your commander.

Chart a Course

Draw two cards. Then discard a card unless you attacked this turn.

Uro, Titan of Nature's Wrath

When Uro enters, sacrifice it unless it escaped.
Whenever Uro enters or attacks, you gain 3 life and draw a card, then you may put a land card from your hand onto the battlefield.
Escape—{G}{G}{U}{U}, Exile five other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Ulvenwald Behemoth

Trample, haste
Other creatures you control get +1/+1 and have trample and haste.

Ulvenwald Oddity

Trample, haste
{5}{G}{G}: Transform Ulvenwald Oddity.

Ulvenwald Oddity // Ulvenwald Behemoth

Natural Order

As an additional cost to cast this spell, sacrifice a green creature.
Search your library for a green creature card, put it onto the battlefield, then shuffle.

Steam Vents

({T}: Add {U} or {R}.)
As Steam Vents enters, you may pay 2 life. If you don't, it enters tapped.

Legolas's Quick Reflexes

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Untap target creature. Until end of turn, it gains hexproof, reach, and "Whenever this creature becomes tapped, it deals damage equal to its power to up to one target creature."

Breeding Pool

({T}: Add {G} or {U}.)
As Breeding Pool enters, you may pay 2 life. If you don't, it enters tapped.

Snapcaster Mage

Flash
When Snapcaster Mage enters, target instant or sorcery card in your graveyard gains flashback until end of turn. The flashback cost is equal to its mana cost. (You may cast that card from your graveyard for its flashback cost. Then exile it.)

Arasta of the Endless Web

Reach
Whenever an opponent casts an instant or sorcery spell, create a 1/2 green Spider creature token with reach.

Mana Drain

Counter target spell. At the beginning of your next main phase, add an amount of {C} equal to that spell's mana value.

Force of Negation

If it's not your turn, you may exile a blue card from your hand rather than pay this spell's mana cost.
Counter target noncreature spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Titania, Protector of Argoth

When Titania, Protector of Argoth enters, return target land card from your graveyard to the battlefield.
Whenever a land you control is put into a graveyard from the battlefield, create a 5/3 green Elemental creature token.

Stomping Ground

({T}: Add {R} or {G}.)
As Stomping Ground enters, you may pay 2 life. If you don't, it enters tapped.

Stern Scolding

Counter target creature spell with power or toughness 2 or less.

Botanical Sanctum

Botanical Sanctum enters tapped unless you control two or fewer other lands.
{T}: Add {G} or {U}.

Sentinel of the Nameless City

Vigilance
Whenever Sentinel of the Nameless City enters or attacks, create a Map token. (It's an artifact with "{1}, {T}, Sacrifice this artifact: Target creature you control explores. Activate only as a sorcery.")

Llanowar Elves

Birds of Paradise

Hexdrinker

Level up {1} ({1}: Put a level counter on this. Level up only as a sorcery.)
LEVEL 3-7
4/4
Protection from instants
LEVEL 8+
6/6
Protection from everything

Waterlogged Grove

{T}, Pay 1 life: Add {G} or {U}.
{1}, {T}, Sacrifice Waterlogged Grove: Draw a card.

Copperline Gorge

Copperline Gorge enters tapped unless you control two or fewer other lands.
{T}: Add {R} or {G}.

Jace, Telepath Unbound

+1: Up to one target creature gets -2/-0 until your next turn.
−3: You may cast target instant or sorcery card from your graveyard this turn. If that spell would be put into your graveyard, exile it instead.
−9: You get an emblem with "Whenever you cast a spell, target opponent mills five cards."

Jace, Vryn's Prodigy

{T}: Draw a card, then discard a card. If there are five or more cards in your graveyard, exile Jace, Vryn's Prodigy, then return him to the battlefield transformed under his owner's control.

Jace, Vryn's Prodigy // Jace, Telepath Unbound

Boseiju, Who Endures

{T}: Add {G}.
Channel — {1}{G}, Discard Boseiju, Who Endures: Destroy target artifact, enchantment, or nonbasic land an opponent controls. That player may search their library for a land card with a basic land type, put it onto the battlefield, then shuffle. This ability costs {1} less to activate for each legendary creature you control.

Gruff Triplets

Trample
When Gruff Triplets enters, if it isn't a token, create two tokens that are copies of it.
When Gruff Triplets dies, put a number of +1/+1 counters equal to its power on each creature you control named Gruff Triplets.

Gaea's Cradle

{T}: Add {G} for each creature you control.

Delighted Halfling

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a legendary spell, and that spell can't be countered.

Forest

Ponder

Look at the top three cards of your library, then put them back in any order. You may shuffle.
Draw a card.

The One Ring

Indestructible
When The One Ring enters, if you cast it, you gain protection from everything until your next turn.
At the beginning of your upkeep, you lose 1 life for each burden counter on The One Ring.
{T}: Put a burden counter on The One Ring, then draw a card for each burden counter on The One Ring.

Island

Crop Rotation

As an additional cost to cast this spell, sacrifice a land.
Search your library for a land card, put that card onto the battlefield, then shuffle.

Arid Mesa

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