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.

Blossom Dryad

Dutiful Replicator

When Dutiful Replicator enters the battlefield, you may pay {1}. When you do, create a token that's a copy of target token you control not named Dutiful Replicator.

Kiora's Follower

Volo, Itinerant Scholar

When Volo enters the battlefield, create Volo's Journal, a legendary colorless artifact token with hexproof and "Whenever you cast a creature spell, note one of its creature types that hasn't been noted for this artifact."
{2}, {T}: Draw a card for each creature type noted for target permanent you control named Volo's Journal.
Choose a Background

Garruk's Packleader

Whenever another creature with power 3 or greater enters the battlefield under your control, you may draw a card.

Argothian Sprite

Argothian Sprite can't be blocked by artifact creatures.
{7}: Put two +1/+1 counters on Argothian Sprite.

Grazing Gladehart

Landfall — Whenever a land enters the battlefield under your control, you may gain 2 life.

Stone-Tongue Basilisk

Whenever Stone-Tongue Basilisk deals combat damage to a creature, destroy that creature at end of combat.
Threshold — As long as seven or more cards are in your graveyard, all creatures able to block Stone-Tongue Basilisk do so.

Almighty Brushwagg

Trample
{3}{G}: Almighty Brushwagg gets +3/+3 until end of turn.

Keeper of Fables

Whenever one or more non-Human creatures you control deal combat damage to a player, draw a card.

Bull Hippo

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

Rampant Growth

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

Bull Aurochs

Trample
Whenever Bull Aurochs attacks, it gets +1/+0 until end of turn for each other attacking Aurochs.

Peregrine Drake

Flying
When Peregrine Drake enters the battlefield, untap up to five lands.

Centaur Chieftain

Haste
Threshold — As long as seven or more cards are in your graveyard, Centaur Chieftain has "When Centaur Chieftain enters the battlefield, creatures you control get +1/+1 and gain trample until end of turn."

Clay Golem

{6}, Roll a d8: Monstrosity X, where X is the result. (If this creature isn't monstrous, put X +1/+1 counters on it and it becomes monstrous.)
Berserk — When Clay Golem becomes monstrous, destroy target permanent.

Arcane Signet

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

Arbor Colossus

Reach
{3}{G}{G}{G}: Monstrosity 3. (If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.)
When Arbor Colossus becomes monstrous, destroy target creature with flying an opponent controls.

Horizon Chimera

Flash
Flying, trample
Whenever you draw a card, you gain 1 life.

Radagast the Brown

Whenever Radagast the Brown or another nontoken creature enters the battlefield under your control, look at the top X cards of your library, where X is that creature's mana value. You may reveal a creature card that doesn't share a creature type with a creature you control from among those cards and put it into your hand. Put the rest on the bottom of your library in a random order.

Skittering Crustacean

{6}{U}: Monstrosity 4. (If this creature isn't monstrous, put four +1/+1 counters on it and it becomes monstrous.)
As long as Skittering Crustacean is monstrous, it has hexproof. (It can't be the target of spells or abilities your opponents control.)

Locthwain Gargoyle

{4}: Locthwain Gargoyle gets +2/+0 and gains flying until end of turn.

Compass Gnome

When Compass Gnome enters the battlefield, you may search your library for a basic land card or Cave card, reveal it, then shuffle and put that card on top.

Poison Dart Frog

Reach
{T}: Add one mana of any color.
{2}: Poison Dart Frog gains deathtouch until end of turn.

Volo, Guide to Monsters

Whenever you cast a creature spell that doesn't share a creature type with a creature you control or a creature card in your graveyard, copy that spell. (A copy of a creature spell becomes a token.)

Fleet Swallower

Whenever Fleet Swallower attacks, target player mills half their library, rounded up.

Biomancer's Familiar

Activated abilities of creatures you control cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.
{T}: The next time target creature adapts this turn, it adapts as though it had no +1/+1 counters on it.

Towering Gibbon

Reach
Towering Gibbon's power is equal to the greatest mana value among creatures you control.

Quicksilver Elemental

{U}: Quicksilver Elemental gains all activated abilities of target creature until end of turn. (If any of the abilities use that creature's name, use this creature's name instead.)
You may spend blue mana as though it were mana of any color to pay the activation costs of Quicksilver Elemental's abilities.

Burnished Hart

{3}, Sacrifice Burnished Hart: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Long List of the Ents

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after VI.)
I, II, III, IV, V, VI — Note a creature type that hasn't been noted for Long List of the Ents. When you next cast a creature spell of that type this turn, that creature enters the battlefield with an additional +1/+1 counter on it.

Simic Signet

Basking Capybara

Descend 4 — Basking Capybara gets +3/+0 as long as there are four or more permanent cards in your graveyard.

Owlbear Cub

Mama's Coming — Whenever Owlbear Cub attacks a player who controls eight or more lands, look at the top eight cards of your library. You may put a creature card from among them onto the battlefield tapped and attacking that player. Put the rest on the bottom of your library in a random order.

Gnoll Hunter

Pack tactics — Whenever Gnoll Hunter attacks, if you attacked with creatures with total power 6 or greater this combat, put a +1/+1 counter on Gnoll Hunter.

Nessian Boar

All creatures able to block Nessian Boar do so.
Whenever Nessian Boar becomes blocked by a creature, that creature's controller draws a card.

Omen Hawker

{T}: Add {C}{U}. Spend this mana only to activate abilities.

Rysorian Badger

Whenever Rysorian Badger attacks and isn't blocked, you may exile up to two target creature cards from defending player's graveyard. If you do, you gain 1 life for each card exiled this way and Rysorian Badger assigns no combat damage this turn.

Druid of the Emerald Grove

When Druid of the Emerald Grove enters the battlefield, search your library for up to two basic land cards and reveal them, then roll a d20.
9 or less | Put those cards into your hand, then shuffle.
10—19 | Put one of those cards onto the battlefield tapped and the other into your hand, then shuffle.
20+ | Put those cards onto the battlefield tapped, then shuffle.

Foe-Razer Regent

Flying
When Foe-Razer Regent enters the battlefield, you may have it fight target creature you don't control.
Whenever a creature you control fights, put two +1/+1 counters on it at the beginning of the next end step.

Sewer Crocodile

{3}{U}: Sewer Crocodile can't be blocked this turn. This ability costs {3} less to activate if there are five or more mana values among cards in your graveyard.

Fleetfeather Cockatrice

Flash (You may cast this spell any time you could cast an instant.)
Flying, deathtouch
{5}{G}{U}: Monstrosity 3. (If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.)

Rot Shambler

Whenever another creature you control dies, put a +1/+1 counter on Rot Shambler.

Audience with Trostani

Create a 0/1 green Plant creature token, then draw cards equal to the number of differently named creature tokens you control.

Terastodon

When Terastodon enters the battlefield, you may destroy up to three target noncreature permanents. For each permanent put into a graveyard this way, its controller creates a 3/3 green Elephant creature token.