Molten-Tail Masticore

At the beginning of your upkeep, sacrifice Molten-Tail Masticore unless you discard a card.
{4}, Exile a creature card from your graveyard: Molten-Tail Masticore deals 4 damage to any target.
{2}: Regenerate Molten-Tail Masticore.

Urza's Avenger

{0}: Urza's Avenger gets -1/-1 and gains your choice of banding, flying, first strike, or trample until end of turn. (Any creatures with banding, and up to one without, can attack in a band. Bands are blocked as a group. If any creatures with banding you control are blocking or being blocked by a creature, you divide that creature's combat damage, not its controller, among any of the creatures it's being blocked by or is blocking.)

Simic Ragworm

Fledgling Mawcor

Flying
{T}: Fledgling Mawcor deals 1 damage to any target.
Morph {U}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Llanowar Visionary

When Llanowar Visionary enters, draw a card.
{T}: Add {G}.

Thornwind Faeries

Flying
{T}: Thornwind Faeries deals 1 damage to any target.

Ornithopter of Paradise

Reclusive Taxidermist

Reclusive Taxidermist gets +3/+2 as long as there are four or more creature cards in your graveyard.
{T}: Add one mana of any color.

Water Servant

{U}: Water Servant gets +1/-1 until end of turn.
{U}: Water Servant gets -1/+1 until end of turn.

Silvos, Rogue Elemental

Trample
{G}: Regenerate Silvos, Rogue Elemental.

Scuttlemutt

{T}: Add one mana of any color.
{T}: Target creature becomes the color or colors of your choice until end of turn.

Naga Vitalist

{T}: Add one mana of any type that a land you control could produce.

Shorecrasher Elemental

{U}: Exile Shorecrasher Elemental, then return it to the battlefield face down under its owner's control.
{1}: Shorecrasher Elemental gets +1/-1 or -1/+1 until end of turn.
Megamorph {4}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)

Alloy Myr

Worldly Tutor

Search your library for a creature card, reveal it, then shuffle and put the card on top.

Pentavus

Pentavus enters with five +1/+1 counters on it.
{1}, Remove a +1/+1 counter from Pentavus: Create a 1/1 colorless Pentavite artifact creature token with flying.
{1}, Sacrifice a Pentavite: Put a +1/+1 counter on Pentavus.

Aetherling

{U}: Exile Aetherling. Return it to the battlefield under its owner's control at the beginning of the next end step.
{U}: Aetherling can't be blocked this turn.
{1}: Aetherling gets +1/-1 until end of turn.
{1}: Aetherling gets -1/+1 until end of turn.

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.

Gemhide Sliver

All Slivers have "{T}: Add one mana of any color."

Archivist

Suq'Ata Firewalker

Suq'Ata Firewalker can't be the target of red spells or abilities from red sources.
{T}: Suq'Ata Firewalker deals 1 damage to any target.

Utopia Tree

Lunar Avenger

Sunburst (This enters with a +1/+1 counter on it for each color of mana spent to cast it.)
Remove a +1/+1 counter from Lunar Avenger: Lunar Avenger gains your choice of flying, first strike, or haste until end of turn.

Wild Mongrel

Discard a card: Wild Mongrel gets +1/+1 and becomes the color of your choice until end of turn.

Mindless Automaton

Mindless Automaton enters with two +1/+1 counters on it.
{1}, Discard a card: Put a +1/+1 counter on Mindless Automaton.
Remove two +1/+1 counters from Mindless Automaton: Draw a card.

Shifting Ceratops

This spell can't be countered.
Protection from blue (This creature can't be blocked, targeted, dealt damage, enchanted, or equipped by anything blue.)
{G}: Shifting Ceratops gains your choice of reach, trample, or haste until end of turn.

Plaxcaster Frogling

Graft 3 (This creature enters with three +1/+1 counters on it. Whenever another creature enters, you may move a +1/+1 counter from this creature onto it.)
{2}: Target creature with a +1/+1 counter on it gains shroud until end of turn. (It can't be the target of spells or abilities.)

Krakilin

Krakilin enters with X +1/+1 counters on it.
{1}{G}: Regenerate Krakilin.

Courtly Provocateur

{T}: Target creature attacks this turn if able.
{T}: Target creature blocks this turn if able.

Sparkhunter Masticore

As an additional cost to cast this spell, discard a card.
Protection from planeswalkers
{1}: Sparkhunter Masticore deals 1 damage to target planeswalker.
{3}: Sparkhunter Masticore gains indestructible until end of turn.

Mawcor

Flying
{T}: Mawcor deals 1 damage to any target.

Paradise Druid

This creature has hexproof as long as it's untapped. (It can't be the target of spells or abilities your opponents control.)
{T}: Add one mana of any color.

Heartstone

Activated abilities of creatures cost {1} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Soliton

Zimone, Quandrix Prodigy

{1}, {T}: You may put a land card from your hand onto the battlefield tapped.
{4}, {T}: Draw a card. If you control eight or more lands, draw two cards instead.

Lifespring Druid

Silhana Starfletcher

Reach (This creature can block creatures with flying.)
As Silhana Starfletcher enters, choose a color.
{T}: Add one mana of the chosen color.

Patchwork Crawler

{2}{U}: Exile target creature card from your graveyard and put a +1/+1 counter on Patchwork Crawler.
Patchwork Crawler has all activated abilities of all creature cards exiled with it.

Rings of Brighthearth

Whenever you activate an ability, if it isn't a mana ability, you may pay {2}. If you do, copy that ability. You may choose new targets for the copy.

Arcanis the Omnipotent

{T}: Draw three cards.
{2}{U}{U}: Return Arcanis to its owner's hand.

Futurist Operative

As long as Futurist Operative is tapped, it's a Human Citizen with base power and toughness 1/1 and can't be blocked.
{2}{U}: Untap Futurist Operative.

Quirion Elves

As Quirion Elves enters, choose a color.
{T}: Add {G}.
{T}: Add one mana of the chosen color.

Jodah's Avenger

{0}: Until end of turn, Jodah's Avenger gets -1/-1 and gains your choice of double strike, protection from red, vigilance, or shadow. (A creature with shadow can block or be blocked by only creatures with shadow.)

Thornling

{G}: Thornling gains haste until end of turn.
{G}: Thornling gains trample until end of turn.
{G}: Thornling gains indestructible until end of turn.
{1}: Thornling gets +1/-1 until end of turn.
{1}: Thornling gets -1/+1 until end of turn.

Rootwater Hunter

{T}: Rootwater Hunter deals 1 damage to any target.

Wolfir Avenger

Flash (You may cast this spell any time you could cast an instant.)
{1}{G}: Regenerate Wolfir Avenger.

Sporeback Troll

Graft 2 (This creature enters with two +1/+1 counters on it. Whenever another creature enters, you may move a +1/+1 counter from this creature onto it.)
{1}{G}: Regenerate target creature with a +1/+1 counter on it.

Death-Hood Cobra

{1}{G}: Death-Hood Cobra gains reach until end of turn.
{1}{G}: Death-Hood Cobra gains deathtouch until end of turn.

Quirion Explorer

{T}: Add one mana of any color that a land an opponent controls could produce.

Drover of the Mighty

Drover of the Mighty gets +2/+2 as long as you control a Dinosaur.
{T}: Add one mana of any color.

Trench Behemoth

Return a land you control to its owner's hand: Untap Trench Behemoth. It gains hexproof until end of turn.
Landfall — Whenever a land you control enters, target creature an opponent controls attacks during its controller's next combat phase if able.

Troll Ascetic

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
{1}{G}: Regenerate Troll Ascetic.

Vigilant Drake

Overgrown Arch

Defender
{T}: You gain 1 life.
{2}, Sacrifice Overgrown Arch: Learn. (You may reveal a Lesson card you own from outside the game and put it into your hand, or discard a card to draw a card.)

Suncrusher

Sunburst (This enters with a +1/+1 counter on it for each color of mana spent to cast it.)
{4}, {T}, Remove a +1/+1 counter from Suncrusher: Destroy target creature.
{2}, Remove a +1/+1 counter from Suncrusher: Return Suncrusher to its owner's hand.

Somberwald Sage

{T}: Add three mana of any one color. Spend this mana only to cast creature spells.

Rift Sower

{T}: Add one mana of any color.
Suspend 2—{G} (Rather than cast this card from your hand, you may pay {G} and exile it with two time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost. It has haste.)

Glimmerbell

Prodigal Sorcerer

{T}: Prodigal Sorcerer deals 1 damage to any target.

Grappling Sundew

Defender, reach
{4}{G}: Grappling Sundew gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy this creature.)

Mantis Engine

{2}: Mantis Engine gains flying until end of turn. (It can't be blocked except by creatures with flying or reach.)
{2}: Mantis Engine gains first strike until end of turn. (It deals combat damage before creatures without first strike.)

Horseshoe Crab

Sylvok Explorer

Experiment Kraj

Experiment Kraj has all activated abilities of each other creature with a +1/+1 counter on it.
{T}: Put a +1/+1 counter on target creature.

Bronze Walrus

When Bronze Walrus enters, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)
{T}: Add one mana of any color.

Harvester Druid

{T}: Add one mana of any color that a land you control could produce.

Oviya Pashiri, Sage Lifecrafter

{2}{G}, {T}: Create a 1/1 colorless Servo artifact creature token.
{4}{G}, {T}: Create an X/X colorless Construct artifact creature token, where X is the number of creatures you control.

Devoted Druid

{T}: Add {G}.
Put a -1/-1 counter on Devoted Druid: Untap Devoted Druid.

Spike Feeder

Spike Feeder enters with two +1/+1 counters on it.
{2}, Remove a +1/+1 counter from Spike Feeder: Put a +1/+1 counter on target creature.
Remove a +1/+1 counter from Spike Feeder: You gain 2 life.

Blizzard Elemental

Triskelion

Triskelion enters with three +1/+1 counters on it.
Remove a +1/+1 counter from Triskelion: It deals 1 damage to any target.

Whisperer of the Wilds

{T}: Add {G}.
Ferocious — {T}: Add {G}{G}. Activate only if you control a creature with power 4 or greater.

Thopter Squadron

Flying
Thopter Squadron enters with three +1/+1 counters on it.
{1}, Remove a +1/+1 counter from Thopter Squadron: Create a 1/1 colorless Thopter artifact creature token with flying. Activate only as a sorcery.
{1}, Sacrifice another Thopter: Put a +1/+1 counter on Thopter Squadron. Activate only as a sorcery.

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.)

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.

Hunted Troll

When Hunted Troll enters, target opponent creates four 1/1 blue Faerie creature tokens with flying.
{G}: Regenerate Hunted Troll.

Locust Swarm

Flying
{G}: Regenerate Locust Swarm.
{G}: Untap Locust Swarm. Activate only once each turn.