Tainted Observer + Ashnod's Altar + Herd Baloth

Tainted Observer
Ashnod's Altar
Herd Baloth

Requires
Tainted Observer must be on the battlefield. Ashnod's Altar must be on the battlefield. Herd Baloth must be on the battlefield. You have a way to cause a creature to enter the battlefield under your control. Herd Baloth has at least one +1/+1 counter on it.
Steps
  1. Cause a creature to enter the battlefield under your control.
  2. When the creature enters the battlefield, Tainted Observer triggers.
  3. Holding priority, activate Ashnod's Altar by sacrificing the creature, adding .
  4. Resolve the Tainted Observer trigger, causing you to pay 2 to put a +1/+1 counter on Herd Baloth.
  5. Herd Baloth triggers, creating a 4/4 Beast creature token.
  6. Repeat from step 2.
Results
Infinite +1/+1 counters on Herd Baloth. Infinite death triggers. Infinite ETB. Infinite LTB. Infinite proliferate. Infinite sacrifice triggers.

Tawnos, the Toymaker
0.09% of 2183 decks 2 decks
Pir, Imaginative Rascal // Toothy, Imaginary Friend
0.04% of 2753 decks 1 decks
Xavier Sal, Infested Captain
0.03% of 3685 decks 1 decks
Falco Spara, Pactweaver
0.02% of 4721 decks 1 decks
The Wise Mothman
0.01% of 10342 decks 1 decks
Atraxa, Praetors' Voice
0.00% of 34224 decks 1 decks
New Cards
Tender Wildguide
100% of 1 decks +98% synergy
Twenty-Toed Toad
100% of 1 decks +93% synergy
Top Cards
Bloated Contaminator
57% of 7 decks +56% synergy
Thrummingbird
57% of 7 decks +55% synergy
Farseek
57% of 7 decks +41% synergy
Counterspell
57% of 7 decks +36% synergy
Swiftfoot Boots
57% of 7 decks +29% synergy
Creatures
Dreamtide Whale
100% of 2 decks +97% synergy
Kitchen Finks
50% of 2 decks +50% synergy
Vizier of Remedies
50% of 2 decks +50% synergy
Azor's Elocutors
50% of 2 decks +50% synergy
Annex Sentry
50% of 2 decks +50% synergy
Glorious Protector
50% of 2 decks +50% synergy
Knight of Autumn
50% of 2 decks +49% synergy
Luminarch Aspirant
50% of 2 decks +49% synergy
Conclave Mentor
50% of 2 decks +49% synergy
Luminous Broodmoth
50% of 2 decks +49% synergy
Agent Frank Horrigan
50% of 2 decks +49% synergy
Archangel of Thune
50% of 2 decks +49% synergy
Mikaeus, the Lunarch
50% of 2 decks +49% synergy
Basking Broodscale
50% of 2 decks +49% synergy
Noble Hierarch
50% of 2 decks +48% synergy
Ranger-Captain of Eos
50% of 2 decks +48% synergy
Aven Mindcensor
50% of 2 decks +48% synergy
Ulamog, the Defiler
50% of 2 decks +47% synergy
Kami of Whispered Hopes
50% of 6 decks +46% synergy
Ivy Lane Denizen
43% of 7 decks +42% synergy
Scurry Oak
43% of 7 decks +42% synergy
Fathom Mage
43% of 7 decks +42% synergy
Ezuri, Stalker of Spheres
43% of 7 decks +42% synergy
Devoted Druid
43% of 7 decks +41% synergy
Tekuthal, Inquiry Dominus
43% of 7 decks +41% synergy
Flux Channeler
43% of 7 decks +41% synergy
Incubation Druid
43% of 7 decks +40% synergy
Soul Diviner
33% of 3 decks +33% synergy
Axebane Ferox
33% of 3 decks +33% synergy
Scheming Aspirant
33% of 3 decks +33% synergy
Meren of Clan Nel Toth
33% of 3 decks +33% synergy
Muldrotha, the Gravetide
33% of 3 decks +33% synergy
Mazirek, Kraul Death Priest
33% of 3 decks +33% synergy
Feral Ghoul
33% of 3 decks +33% synergy
Toxrill, the Corrosive
33% of 3 decks +33% synergy
Sheoldred
33% of 3 decks +31% synergy
Syr Konrad, the Grim
33% of 3 decks +29% synergy
Mirkwood Bats
33% of 3 decks +27% synergy
Krosan Warchief
29% of 7 decks +28% synergy
Biovisionary
29% of 7 decks +28% synergy
Ulvenwald Oddity
29% of 7 decks +28% synergy
Vorel of the Hull Clade
29% of 7 decks +28% synergy
Garruk's Packleader
29% of 7 decks +28% synergy
Thunderfoot Baloth
29% of 7 decks +28% synergy
Master Biomancer
29% of 7 decks +28% synergy
Biophagus
29% of 7 decks +28% synergy
Deepglow Skate
29% of 7 decks +28% synergy
Manglehorn
29% of 7 decks +27% synergy
Herald of Secret Streams
29% of 7 decks +27% synergy
Kodama of the East Tree
29% of 7 decks +27% synergy
Instants
Permission Denied
100% of 1 decks +99% synergy
Anguished Unmaking
100% of 1 decks +94% synergy
Scout's Warning
50% of 2 decks +50% synergy
Radstorm
50% of 4 decks +49% synergy
Atomize
50% of 2 decks +48% synergy
Eerie Interlude
50% of 2 decks +48% synergy
Unbreakable Formation
50% of 2 decks +47% synergy
Dovin's Veto
50% of 2 decks +46% synergy
Swords to Plowshares
50% of 2 decks +21% synergy
Inspiring Call
43% of 7 decks +39% synergy
Countersquall
33% of 3 decks +33% synergy
Vraska's Fall
33% of 3 decks +32% synergy
Baleful Mastery
33% of 3 decks +32% synergy
Bitter Triumph
33% of 3 decks +31% synergy
Assassin's Trophy
33% of 3 decks +27% synergy
Vampiric Tutor
33% of 3 decks +24% synergy
Simic Charm
29% of 7 decks +28% synergy
Resculpt
29% of 7 decks +26% synergy
Rapid Hybridization
29% of 7 decks +24% synergy
Nature's Claim
29% of 7 decks +24% synergy
Growth Spiral
29% of 7 decks +24% synergy
Pongify
29% of 7 decks +23% synergy
Negate
29% of 7 decks +17% synergy
Heroic Intervention
29% of 7 decks +15% synergy
Beast Within
29% of 7 decks +10% synergy
Ripples of Potential
25% of 4 decks +23% synergy
Winged Portent
14% of 7 decks +14% synergy
Masterful Replication
14% of 7 decks +14% synergy
Quandrix Command
14% of 7 decks +14% synergy
Decisive Denial
14% of 7 decks +14% synergy
Solidarity of Heroes
14% of 7 decks +14% synergy
Druid's Deliverance
14% of 7 decks +14% synergy
Jaheira's Respite
14% of 7 decks +14% synergy
Wrap in Vigor
14% of 7 decks +13% synergy
Perplexing Test
14% of 7 decks +13% synergy
Prologue to Phyresis
14% of 7 decks +13% synergy
Infectious Bite
14% of 7 decks +13% synergy
Experimental Augury
14% of 7 decks +13% synergy
Second Harvest
14% of 7 decks +12% synergy
Dispel
14% of 7 decks +12% synergy
Aetherize
14% of 7 decks +12% synergy
Return to Nature
14% of 7 decks +11% synergy
Krosan Grip
14% of 7 decks +10% synergy
Reality Shift
14% of 7 decks +10% synergy
Cyclonic Rift
14% of 7 decks +0% synergy
Sorceries
Damning Verdict
50% of 2 decks +49% synergy
Sevinne's Reclamation
50% of 2 decks +47% synergy
Three Visits
43% of 7 decks +31% synergy
Nature's Lore
43% of 7 decks +28% synergy
Rampant Growth
43% of 7 decks +27% synergy
Spread the Sickness
33% of 3 decks +33% synergy
Phyresis Outbreak
33% of 3 decks +32% synergy
Doppelgang
33% of 3 decks +32% synergy
Drown in Ichor
33% of 3 decks +32% synergy
Infectious Inquiry
33% of 3 decks +32% synergy
Grim Tutor
33% of 3 decks +31% synergy
Toxic Deluge
33% of 3 decks +25% synergy
Demonic Tutor
33% of 3 decks +22% synergy
Smell Fear
29% of 7 decks +28% synergy
Rite of Replication
29% of 7 decks +27% synergy
Unnatural Restoration
29% of 7 decks +26% synergy
Explore
29% of 7 decks +24% synergy
Cultivate
29% of 7 decks +7% synergy
Planewide Celebration
14% of 7 decks +14% synergy
Replication Technique
14% of 7 decks +14% synergy
March of Progress
14% of 7 decks +14% synergy
Expand the Sphere
14% of 7 decks +14% synergy
Thirsting Roots
14% of 7 decks +13% synergy
Ezuri's Predation
14% of 7 decks +13% synergy
Migration Path
14% of 7 decks +13% synergy
Tezzeret's Gambit
14% of 7 decks +12% synergy
Curse of the Swine
14% of 7 decks +12% synergy
Distant Melody
14% of 7 decks +12% synergy
Bala Ged Recovery
14% of 7 decks +10% synergy
Shamanic Revelation
14% of 7 decks +10% synergy
Kodama's Reach
14% of 7 decks -1% synergy
Utility Artifacts
Ghost Lantern
33% of 3 decks +33% synergy
Ozolith, the Shattered Spire
33% of 6 decks +30% synergy
Lux Cannon
29% of 7 decks +28% synergy
Magistrate's Scepter
29% of 7 decks +28% synergy
Combine Chrysalis
29% of 7 decks +28% synergy
Animation Module
29% of 7 decks +28% synergy
Blade of the Bloodchief
29% of 7 decks +28% synergy
Contagion Engine
29% of 7 decks +27% synergy
Altar of Dementia
29% of 7 decks +26% synergy
The Ozolith
29% of 7 decks +25% synergy
The Millennium Calendar
25% of 4 decks +24% synergy
Darksteel Reactor
14% of 7 decks +14% synergy
Weatherlight Compleated
14% of 7 decks +14% synergy
Spawning Pit
14% of 7 decks +14% synergy
Crystal Shard
14% of 7 decks +14% synergy
Doubling Cube
14% of 7 decks +14% synergy
Resurrection Orb
14% of 7 decks +14% synergy
Mask of Avacyn
14% of 7 decks +14% synergy
Magewright's Stone
14% of 7 decks +14% synergy
Thornbite Staff
14% of 7 decks +13% synergy
Krark-Clan Ironworks
14% of 7 decks +13% synergy
Sword of Truth and Justice
14% of 7 decks +13% synergy
Thousand-Year Elixir
14% of 7 decks +12% synergy
Sword of Hearth and Home
14% of 7 decks +12% synergy
Maskwood Nexus
14% of 7 decks +11% synergy
Urza's Incubator
14% of 7 decks +11% synergy
Whispersilk Cloak
14% of 7 decks +10% synergy
Idol of Oblivion
14% of 7 decks +10% synergy
The Great Henge
14% of 7 decks +10% synergy
Sensei's Divining Top
14% of 7 decks +8% synergy
Wayfarer's Bauble
14% of 7 decks +4% synergy
Skullclamp
14% of 7 decks +2% synergy
Lightning Greaves
14% of 7 decks -11% synergy
Enchantments
Battle of Hoover Dam
100% of 1 decks +100% synergy
Together Forever
50% of 2 decks +49% synergy
Greater Auramancy
50% of 2 decks +49% synergy
Aura Shards
50% of 2 decks +48% synergy
Cathars' Crusade
50% of 2 decks +47% synergy
Necrosynthesis
33% of 3 decks +33% synergy
Promise of Aclazotz
33% of 3 decks +33% synergy
Animate Dead
33% of 3 decks +29% synergy
Simic Ascendancy
29% of 7 decks +27% synergy
Parallel Lives
29% of 7 decks +25% synergy
Hardened Scales
29% of 7 decks +25% synergy
Doubling Season
29% of 7 decks +24% synergy
Tribute to the World Tree
17% of 6 decks +12% synergy
Paradox Zone
14% of 7 decks +14% synergy
Curse of Clinging Webs
14% of 7 decks +14% synergy
In Search of Greatness
14% of 7 decks +14% synergy
Primeval Bounty
14% of 7 decks +14% synergy
Death's Presence
14% of 7 decks +14% synergy
Pemmin's Aura
14% of 7 decks +14% synergy
Master Chef
14% of 7 decks +13% synergy
Intruder Alarm
14% of 7 decks +13% synergy
Freed from the Real
14% of 7 decks +13% synergy
Hydra's Growth
14% of 7 decks +13% synergy
Abundance
14% of 7 decks +13% synergy
Mechanized Production
14% of 7 decks +13% synergy
Inexorable Tide
14% of 7 decks +13% synergy
Imprisoned in the Moon
14% of 7 decks +12% synergy
Wizard Class
14% of 7 decks +12% synergy
Reconnaissance Mission
14% of 7 decks +12% synergy
Reflections of Littjara
14% of 7 decks +12% synergy
Beastmaster Ascension
14% of 7 decks +12% synergy
Utopia Sprawl
14% of 7 decks +11% synergy
Wild Growth
14% of 7 decks +9% synergy
Garruk's Uprising
14% of 7 decks +7% synergy
Rhystic Study
14% of 7 decks +0% synergy
Battles
Invasion of Pyrulea
20% of 5 decks +20% synergy
Planeswalkers
Teferi, Time Raveler
50% of 2 decks +49% synergy
Liliana Vess
33% of 3 decks +33% synergy
Liliana of the Veil
33% of 3 decks +33% synergy
Tyvar, Jubilant Brawler
33% of 3 decks +32% synergy
Vraska, Betrayal's Sting
33% of 3 decks +31% synergy
Kiora, Master of the Depths
14% of 7 decks +14% synergy
Garruk, Unleashed
14% of 7 decks +14% synergy
Jiang Yanggu, Wildcrafter
14% of 7 decks +14% synergy
Vivien, Monsters' Advocate
14% of 7 decks +14% synergy
Vivien, Champion of the Wilds
14% of 7 decks +13% synergy
Teferi, Master of Time
14% of 7 decks +13% synergy
Garruk, Primal Hunter
14% of 7 decks +13% synergy
Jace, Wielder of Mysteries
14% of 7 decks +12% synergy
Narset, Parter of Veils
14% of 7 decks +12% synergy
Utility Lands
Karn's Bastion
71% of 7 decks +66% synergy
Reliquary Tower
71% of 7 decks +42% synergy
Bojuka Bog
33% of 3 decks +18% synergy
Nesting Grounds
29% of 7 decks +27% synergy
Command Beacon
29% of 7 decks +24% synergy
Hickory Woodlot
14% of 7 decks +14% synergy
Saprazzan Skerry
14% of 7 decks +14% synergy
Novijen, Heart of Progress
14% of 7 decks +14% synergy
Guildless Commons
14% of 7 decks +13% synergy
Minamo, School at Water's Edge
14% of 7 decks +12% synergy
Tyrite Sanctum
14% of 7 decks +12% synergy
Field of Ruin
14% of 7 decks +12% synergy
War Room
14% of 7 decks +8% synergy
Otawara, Soaring City
14% of 7 decks +6% synergy
Yavimaya, Cradle of Growth
14% of 7 decks +5% synergy
Temple of the False God
14% of 7 decks +5% synergy
Rogue's Passage
14% of 7 decks -5% synergy
Mana Artifacts
Sol Ring
71% of 7 decks -13% synergy
Arcane Signet
57% of 7 decks -14% synergy
Everflowing Chalice
43% of 7 decks +38% synergy
Chromatic Lantern
43% of 7 decks +33% synergy
Talisman of Dominance
33% of 3 decks +26% synergy
Pentad Prism
29% of 7 decks +28% synergy
Replicating Ring
29% of 7 decks +27% synergy
Thought Vessel
29% of 7 decks +12% synergy
Pyramid of the Pantheon
14% of 7 decks +14% synergy
Energy Refractor
14% of 7 decks +14% synergy
Machine God's Effigy
14% of 7 decks +14% synergy
Paradise Mantle
14% of 7 decks +14% synergy
Astral Cornucopia
14% of 7 decks +13% synergy
Staff of Compleation
14% of 7 decks +13% synergy
Talisman of Curiosity
14% of 7 decks +12% synergy
Simic Signet
14% of 7 decks +11% synergy
Mox Diamond
14% of 7 decks +10% synergy
Decanter of Endless Water
14% of 7 decks +9% synergy
Chrome Mox
14% of 7 decks +8% synergy
Lotus Petal
14% of 7 decks +8% synergy
Fellwar Stone
14% of 7 decks -7% synergy
Lands
Indatha Triome
100% of 1 decks +97% synergy
Zagoth Triome
100% of 3 decks +97% synergy
Spara's Headquarters
100% of 2 decks +96% synergy
Undergrowth Stadium
100% of 3 decks +94% synergy
Morphic Pool
100% of 3 decks +93% synergy
Temple Garden
100% of 2 decks +91% synergy
Hallowed Fountain
100% of 2 decks +91% synergy
Overgrown Tomb
100% of 3 decks +91% synergy
Command Tower
100% of 7 decks +26% synergy
Hedge Maze
67% of 3 decks +63% synergy
Llanowar Wastes
67% of 3 decks +61% synergy
Drowned Catacomb
67% of 3 decks +60% synergy
Watery Grave
67% of 3 decks +56% synergy
Hinterland Harbor
57% of 7 decks +51% synergy
Rejuvenating Springs
57% of 7 decks +51% synergy
Breeding Pool
57% of 7 decks +48% synergy
Hengegate Pathway
50% of 2 decks +48% synergy
Branchloft Pathway
50% of 2 decks +48% synergy
Savannah
50% of 2 decks +47% synergy
Tundra
50% of 2 decks +47% synergy
Adarkar Wastes
50% of 2 decks +46% synergy
Bountiful Promenade
50% of 2 decks +45% synergy
Sea of Clouds
50% of 2 decks +44% synergy
Dreamroot Cascade
43% of 7 decks +39% synergy
Yavimaya Coast
43% of 7 decks +37% synergy
Lush Oasis
33% of 3 decks +33% synergy
Darkbore Pathway
33% of 3 decks +31% synergy
Clearwater Pathway
33% of 3 decks +31% synergy
Bayou
33% of 3 decks +30% synergy
Deathcap Glade
33% of 3 decks +30% synergy
Underground Sea
33% of 3 decks +30% synergy
Underground River
33% of 3 decks +29% synergy
Shipwreck Marsh
33% of 3 decks +29% synergy
Woodland Cemetery
33% of 3 decks +28% synergy
Thornwood Falls
29% of 7 decks +27% synergy
Waterlogged Grove
29% of 7 decks +27% synergy
Vineglimmer Snarl
29% of 7 decks +26% synergy
Tropical Island
29% of 7 decks +25% synergy
Simic Growth Chamber
29% of 7 decks +24% synergy
Windswept Heath
29% of 7 decks +18% synergy
Misty Rainforest
29% of 7 decks +17% synergy
Exotic Orchard
29% of 7 decks -7% synergy
Skyshroud Forest
14% of 7 decks +14% synergy
Quandrix Campus
14% of 7 decks +14% synergy
Hall of Tagsin
14% of 7 decks +14% synergy
Gemstone Mine
14% of 7 decks +14% synergy
Tanglepool Bridge
14% of 7 decks +14% synergy
Botanical Sanctum
14% of 7 decks +13% synergy
Mirrex
14% of 7 decks +13% synergy
Rimewood Falls
14% of 7 decks +13% synergy