Explore the Underdark

Search your library for up to two basic land cards and/or Gate cards, put them onto the battlefield tapped, then shuffle.
You take the initiative.

Khalni Heart Expedition

Landfall — Whenever a land you control enters, you may put a quest counter on Khalni Heart Expedition.
Remove three quest counters from Khalni Heart Expedition and sacrifice it: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Fowl Strike

Destroy target creature with flying.
Reinforce 2—{2}{G} ({2}{G}, Discard this card: Put two +1/+1 counters on target creature.)

Feral Encounter

Look at the top five cards of your library. You may exile a creature card from among them. Put the rest on the bottom of your library in a random order. You may cast the exiled card this turn. At the beginning of the next combat phase this turn, target creature you control deals damage equal to its power to up to one target creature you don't control.

Root Snare

Prevent all combat damage that would be dealt this turn.

Scab-Clan Charger

Bloodrush — {1}{G}, Discard Scab-Clan Charger: Target attacking creature gets +2/+4 until end of turn.

The Mending of Dominaria

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — Mill two cards, then you may return a creature card from your graveyard to your hand.
III — Return all land cards from your graveyard to the battlefield, then shuffle your graveyard into your library.

Lifespring Druid

Orochi Merge-Keeper

{T}: Add {G}.
As long as Orochi Merge-Keeper is modified, it has "{T}: Add {G}{G}." (Equipment, Auras you control, and counters are modifications.)

Ivy Lane Denizen

Whenever another green creature you control enters, put a +1/+1 counter on target creature.

Elvish Visionary

When Elvish Visionary enters, draw a card.

Sunshower Druid

When Sunshower Druid enters, put a +1/+1 counter on target creature and you gain 1 life.

Plummet

Hitchclaw Recluse

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Full Steam Ahead

Until end of turn, each creature you control gets +2/+2 and gains trample and "This creature can't be blocked by more than one creature."

Map the Frontier

Search your library for up to two basic land cards and/or Desert cards, put them onto the battlefield tapped, then shuffle.

Tough Cookie

When Tough Cookie enters, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")
{2}{G}: Until end of turn, target noncreature artifact you control becomes a 4/4 artifact creature.
{2}, {T}, Sacrifice Tough Cookie: You gain 3 life.

Might of Old Krosa

Target creature gets +2/+2 until end of turn. If you cast this spell during your main phase, that creature gets +4/+4 until end of turn instead.

Jade Orb of Dragonkind

{T}: Add {G}. When you spend this mana to cast a Dragon creature spell, it enters with an additional +1/+1 counter on it and gains hexproof until your next turn. (It can't be the target of spells or abilities your opponents control.)

Goldvein Hydra

Vigilance, trample, haste
Goldvein Hydra enters with X +1/+1 counters on it.
When Goldvein Hydra dies, create a number of tapped Treasure tokens equal to its power.

Tarmogoyf Nest

Enchant land
Enchanted land has "{1}{G}, {T}: Create a Tarmogoyf token." (It's a {1}{G} Lhurgoyf creature with "Tarmogoyf's power is equal to the number of card types among cards in all graveyards and its toughness is equal to that number plus 1.")

Horizon Seeker

Boast — {1}{G}: Search your library for a basic land card, reveal it, put it into your hand, then shuffle. (Activate only if this creature attacked this turn and only once each turn.)

Placid Rottentail

Vigilance
{2}{G}, Exile Placid Rottentail from your graveyard: Put two +1/+1 counters on target creature. Activate only as a sorcery.

Puny Snack

Target creature gets -2/-2 until end of turn. (Then exile this card. You may cast the creature later from exile.)

Gingerbread Hunter

When Gingerbread Hunter enters, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")

Gingerbread Hunter // Puny Snack

Mistbreath Elder

At the beginning of your upkeep, return another creature you control to its owner's hand. If you do, put a +1/+1 counter on Mistbreath Elder. Otherwise, you may return Mistbreath Elder to its owner's hand.

The Ringhart Crest

As The Ringhart Crest enters, choose a creature type.
{T}: Add {G}. Spend this mana only to cast a creature spell of the chosen type or a legendary creature spell.

Kolvori, God of Kinship

As long as you control three or more legendary creatures, Kolvori gets +4/+2 and has vigilance.
{1}{G}, {T}: Look at the top six cards of your library. You may reveal a legendary creature card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Kolvori, God of Kinship // The Ringhart Crest

Deadly Recluse

Reach (This creature can block creatures with flying.)
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Incremental Growth

Put a +1/+1 counter on target creature, two +1/+1 counters on another target creature, and three +1/+1 counters on a third target creature.

Skanos Dragonheart

Whenever Skanos Dragonheart attacks, it gets +X/+X until end of turn, where X is the greatest power among other Dragons you control and Dragon cards in your graveyard.
Choose a Background (You can have a Background as a second commander.)

Coati Scavenger

Descend 4 — When Coati Scavenger enters, if there are four or more permanent cards in your graveyard, return target permanent card from your graveyard to your hand.

Ankle Biter

Elvish Aberration

{T}: Add {G}{G}{G}.
Forestcycling {2} ({2}, Discard this card: Search your library for a Forest card, reveal it, put it into your hand, then shuffle.)

Greater Tanuki

Trample
Channel — {2}{G}, Discard Greater Tanuki: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Raucous Entertainer

{1}, {T}: Put a +1/+1 counter on each creature you control that entered this turn.

Font of Fertility

{1}{G}, Sacrifice Font of Fertility: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Leaping Ambush

Target creature gets +1/+3 and gains reach until end of turn. Untap it.

Signature Slam

Put a +1/+1 counter on target creature you control, then each modified creature you control deals damage equal to its power to target creature you don't control. (Equipment, Auras you control, and counters are modifications.)

Dire-Strain Brawler

Vigilance
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Tireless Hauler

Vigilance
Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

Tireless Hauler // Dire-Strain Brawler

Magnigoth Sentry

Reach (This creature can block creatures with flying.)

Evolution Witness

{1}{G}: Adapt 2. (If this creature has no +1/+1 counters on it, put two +1/+1 counters on it.)
Whenever one or more +1/+1 counters are put on Evolution Witness, return target permanent card from your graveyard to your hand.

Skyscythe Engulfer

Reach, trample
Skyscythe Engulfer can't be blocked by creatures with flying.

Crushing Vines

Choose one —
• Destroy target creature with flying.
• Destroy target artifact.

Quilled Wolf

{5}{G}: Quilled Wolf gets +4/+4 until end of turn.

Bassara Tower Archer

Guardian Gladewalker

Changeling (This card is every creature type.)
When Guardian Gladewalker enters, put a +1/+1 counter on target creature.

Wear Down

Gift a card (You may promise an opponent a gift as you cast this spell. If you do, they draw a card before its other effects.)
Destroy target artifact or enchantment. If the gift was promised, instead destroy two target artifacts and/or enchantments.

Pack Guardian

Flash (You may cast this spell any time you could cast an instant.)
When Pack Guardian enters, you may discard a land card. If you do, create a 2/2 green Wolf creature token.

Portent Tracker

{T}: Untap target land.
{T}: Choose target battle. If an opponent protects it, remove a defense counter from it. Otherwise, put a defense counter on it. Activate only as a sorcery.

Wildwood Rebirth

Return target creature card from your graveyard to your hand.

Timberpack Wolf

Timberpack Wolf gets +1/+1 for each other creature you control named Timberpack Wolf.

Untamed Pup

Trample
Other Wolves and Werewolves you control have trample.
{3}{G}: Put a +1/+1 counter on target creature.
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Hound Tamer

Trample
{3}{G}: Put a +1/+1 counter on target creature.
Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

Hound Tamer // Untamed Pup

Titanic Growth

Target creature gets +4/+4 until end of turn.

Gelatinous Genesis

Freestrider Commando

Freestrider Commando enters with two +1/+1 counters on it if it wasn't cast or no mana was spent to cast it.
Plot {3}{G} (You may pay {3}{G} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Oracle of Mul Daya

You may play an additional land on each of your turns.
Play with the top card of your library revealed.
You may play lands from the top of your library.

Planewide Celebration

Choose four. You may choose the same mode more than once.
• Create a 2/2 Citizen creature token that's all colors.
• Return target permanent card from your graveyard to your hand.
• Proliferate.
• You gain 4 life.

You Meet in a Tavern

Choose one —
• Form a Party — Look at the top five cards of your library. You may reveal any number of creature cards from among them and put them into your hand. Put the rest on the bottom of your library in a random order.
• Start a Brawl — Creatures you control get +2/+2 until end of turn.

Sultai Flayer

Whenever a creature you control with toughness 4 or greater dies, you gain 4 life.

Clifftop Lookout

Reach
When Clifftop Lookout enters, reveal cards from the top of your library until you reveal a land card. Put that card onto the battlefield tapped and the rest on the bottom of your library in a random order.

Soul of the Harvest

Trample
Whenever another nontoken creature you control enters, you may draw a card.

Serpent-Blade Assailant

Backup 1 (When this creature enters, put a +1/+1 counter on target creature. If that's another creature, it gains the following ability until end of turn.)
Deathtouch

Naturalize

Hazardroot Herbalist

Whenever you attack, target creature you control gets +1/+0 until end of turn. If that creature is a token, it also gains deathtouch until end of turn.

Satyr Wayfinder

When Satyr Wayfinder enters, reveal the top four cards of your library. You may put a land card from among them into your hand. Put the rest into your graveyard.

High Stride

Hunt the Weak

Put a +1/+1 counter on target creature you control. Then that creature fights target creature you don't control. (Each deals damage equal to its power to the other.)

Thrive

Put a +1/+1 counter on each of X target creatures.

Pheres-Band Tromper

Inspired — Whenever Pheres-Band Tromper becomes untapped, put a +1/+1 counter on it.

Thornvault Forager

{T}: Add {G}.
{T}, Forage: Add two mana in any combination of colors. (To forage, exile three cards from your graveyard or sacrifice a Food.)
{3}{G}, {T}: Search your library for a Squirrel card, reveal it, put it into your hand, then shuffle.

Curious Forager

When Curious Forager enters, you may forage. When you do, return target permanent card from your graveyard to your hand. (To forage, exile three cards from your graveyard or sacrifice a Food.)

Sight of the Scalelords

At the beginning of combat on your turn, creatures you control with toughness 4 or greater get +2/+2 and gain vigilance until end of turn.

Bounding Wolf

Oran-Rief Invoker

{8}: Oran-Rief Invoker gets +5/+5 and gains trample until end of turn.

Dawnhart Rejuvenator

When Dawnhart Rejuvenator enters, you gain 3 life.
{T}: Add one mana of any color.

Longstalk Brawl

Gift a tapped Fish (You may promise an opponent a gift as you cast this spell. If you do, they create a tapped 1/1 blue Fish creature token before its other effects.)
Choose target creature you control and target creature you don't control. Put a +1/+1 counter on the creature you control if the gift was promised. Then those creatures fight each other.

Littjara Glade-Warden

Changeling (This card is every creature type.)
{2}{G}, {T}, Exile a creature card from your graveyard: Put two +1/+1 counters on target creature. Activate only as a sorcery.

Snapping Gnarlid

Landfall — Whenever a land you control enters, Snapping Gnarlid gets +1/+1 until end of turn.

Rampaging Brontodon

Trample
Whenever Rampaging Brontodon attacks, it gets +1/+1 until end of turn for each land you control.

Malady Invoker

When this creature transforms into Malady Invoker, target creature an opponent controls gets -0/-X until end of turn, where X is Malady Invoker's power.

Herbology Instructor

When Herbology Instructor enters, you gain 3 life.
{6}{B/P}: Transform Herbology Instructor. Activate only as a sorcery. ({B/P} can be paid with either {B} or 2 life.)

Herbology Instructor // Malady Invoker

Centaur Battlemaster

Heroic — Whenever you cast a spell that targets Centaur Battlemaster, put three +1/+1 counters on Centaur Battlemaster.

Wildwood Escort

When Wildwood Escort enters, return target creature or battle card from your graveyard to your hand.
If Wildwood Escort would die, exile it instead.

Fugitive of the Judoon

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Create a 1/1 white Human creature token with ward {2} and a 4/4 white Alien Rhino creature token.
II — Investigate.
III — You may exile a Human you control and an artifact you control. If you do, search your library for a Doctor card, put it onto the battlefield, then shuffle.

Gnarlback Rhino

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Whenever you cast a spell that targets this creature, draw a card.

Obsessive Skinner

When Obsessive Skinner enters, put a +1/+1 counter on target creature.
Delirium — At the beginning of each opponent's upkeep, if there are four or more card types among cards in your graveyard, put a +1/+1 counter on target creature.

Graceful Takedown

Any number of target enchanted creatures you control and up to one other target creature you control each deal damage equal to their power to target creature you don't control.

The Binding of the Titans

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Each player mills three cards.
II — Exile up to two target cards from graveyards. For each creature card exiled this way, you gain 1 life.
III — Return target creature or land card from your graveyard to your hand.

Dawnhart Mentor

When Dawnhart Mentor enters, create a 1/1 white Human creature token.
Coven — {5}{G}: Target creature you control gets +3/+3 and gains trample until end of turn. Activate only if you control three or more creatures with different powers.

Smuggler's Surprise

Spree (Choose one or more additional costs.)
+ {2} — Mill four cards. You may put up to two creature and/or land cards from among the milled cards into your hand.
+ {4}{G} — You may put up to two creature cards from your hand onto the battlefield.
+ {1} — Creatures you control with power 4 or greater gain hexproof and indestructible until end of turn.

Revive the Shire

Return target permanent card from your graveyard to your hand. Create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")

Biogenic Upgrade

Distribute three +1/+1 counters among one, two, or three target creatures, then double the number of +1/+1 counters on each of those creatures.

Up the Beanstalk

When Up the Beanstalk enters and whenever you cast a spell with mana value 5 or greater, draw a card.

Patient Naturalist

When Patient Naturalist enters, mill three cards. Put a land card from among the milled cards into your hand. If you can't, create a Treasure token. (To mill three cards, put the top three cards of your library into your graveyard.)

Tumbleweed Rising

Create an X/X green Elemental creature token, where X is the greatest power among creatures you control.
Plot {2}{G} (You may pay {2}{G} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Broken Wings

Destroy target artifact, enchantment, or creature with flying.

Thornado

Destroy target creature with flying.
Cycling {1}{G} ({1}{G}, Discard this card: Draw a card.)

Nightshade Dryad

Deathtouch
{T}: Add {C}.
{T}: Add one mana of any color.

Genesis Hydra

When you cast this spell, reveal the top X cards of your library. You may put a nonland permanent card with mana value X or less from among them onto the battlefield. Then shuffle the rest into your library.
Genesis Hydra enters with X +1/+1 counters on it.