Tainted Observer + Ashnod's Altar + Scurry Oak

Tainted Observer
Ashnod's Altar
Scurry Oak

Requires
Tainted Observer must be on the battlefield. Ashnod's Altar must be on the battlefield. Scurry Oak must be on the battlefield. You have a way to cause a creature to enter the battlefield under your control. Scurry Oak 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 Scurry Oak.
  5. Scurry Oak triggers, creating a 1/1 Squirrel creature token.
  6. Repeat from step 2.
Results
Infinite +1/+1 counters on Scurry Oak. Infinite death triggers. Infinite ETB. Infinite LTB. Infinite proliferate. Infinite sacrifice triggers.

Xavier Sal, Infested Captain
0.34% of 4674 decks 16 decks
Ezuri, Stalker of Spheres
0.06% of 3486 decks 2 decks
The Wise Mothman
0.02% of 13237 decks 2 decks
Falco Spara, Pactweaver
0.02% of 4610 decks 1 decks
Nadu, Winged Wisdom
0.02% of 5896 decks 1 decks
Atraxa, Praetors' Voice
0.00% of 35660 decks 1 decks
Zellix, Sanity Flayer // Master Chef
2.13% of 47 decks 1 decks
Roalesk, Apex Hybrid
0.17% of 595 decks 1 decks
Lonis, Genetics Expert
0.16% of 625 decks 1 decks
Ezuri, Claw of Progress
0.02% of 6303 decks 1 decks
Volrath, the Shapestealer
0.04% of 2842 decks 1 decks
High Synergy Cards
Tekuthal, Inquiry Dominus
64% of 28 decks +61% synergy
Evolution Sage
68% of 28 decks +61% synergy
Tyvar, Jubilant Brawler
65% of 20 decks +60% synergy
Basking Broodscale
62% of 13 decks +59% synergy
Ezuri, Stalker of Spheres
61% of 28 decks +57% synergy
Intruder Alarm
54% of 28 decks +52% synergy
Thrummingbird
54% of 28 decks +50% synergy
Karn's Bastion
54% of 28 decks +48% synergy
Dreamtide Whale
50% of 10 decks +46% synergy
Emperor of Bones
44% of 9 decks +44% synergy
Top Cards
Everflowing Chalice
50% of 28 decks +45% synergy
Cankerbloom
50% of 28 decks +43% synergy
Mutational Advantage
44% of 18 decks +39% synergy
Flux Channeler
43% of 28 decks +40% synergy
Fathom Mage
43% of 28 decks +39% synergy
Mirkwood Bats
42% of 19 decks +30% synergy
Pitiless Plunderer
40% of 20 decks +32% synergy
Assassin's Trophy
40% of 20 decks +10% synergy
Astral Cornucopia
39% of 28 decks +38% synergy
Tezzeret's Gambit
39% of 28 decks +36% synergy
Creatures
Twenty-Toed Toad
43% of 7 decks +37% synergy
Bloated Contaminator
36% of 28 decks +33% synergy
Venser, Corpse Puppet
35% of 20 decks +34% synergy
Winding Constrictor
35% of 20 decks +31% synergy
Kami of Whispered Hopes
33% of 27 decks +26% synergy
Mycoloth
32% of 28 decks +30% synergy
Gyre Sage
32% of 28 decks +28% synergy
Evolution Witness
31% of 13 decks +26% synergy
Zulaport Cutthroat
30% of 20 decks +20% synergy
Master Biomancer
29% of 28 decks +25% synergy
Utopia Mycon
25% of 28 decks +24% synergy
Walking Ballista
25% of 28 decks +22% synergy
Agent Frank Horrigan
25% of 12 decks +21% synergy
Ivy Lane Denizen
21% of 28 decks +20% synergy
Deepglow Skate
21% of 28 decks +19% synergy
Renata, Called to the Hunt
21% of 28 decks +19% synergy
Venerated Rotpriest
21% of 28 decks +19% synergy
Devoted Druid
21% of 28 decks +18% synergy
Kiora's Follower
21% of 28 decks +16% synergy
Scute Swarm
21% of 28 decks +12% synergy
Scheming Aspirant
20% of 20 decks +19% synergy
Slimefoot, the Stowaway
20% of 20 decks +18% synergy
Toxrill, the Corrosive
20% of 20 decks +17% synergy
Mazirek, Kraul Death Priest
20% of 20 decks +17% synergy
Chatterfang, Squirrel General
20% of 20 decks +15% synergy
Plaguemaw Beast
18% of 28 decks +18% synergy
Herd Baloth
18% of 28 decks +17% synergy
Vorinclex, Monstrous Raider
18% of 28 decks +14% synergy
Chasm Skulker
18% of 28 decks +14% synergy
Spark Double
18% of 28 decks +11% synergy
Birds of Paradise
18% of 28 decks -9% synergy
The Mycotyrant
18% of 17 decks +16% synergy
Gruff Triplets
16% of 25 decks +14% synergy
Deathspore Thallid
15% of 20 decks +14% synergy
Grismold, the Dreadsower
15% of 20 decks +14% synergy
Fain, the Broker
15% of 20 decks +14% synergy
Ichor Rats
15% of 20 decks +13% synergy
Blightbelly Rat
15% of 20 decks +13% synergy
Nemata, Primeval Warden
15% of 20 decks +12% synergy
Corpsejack Menace
15% of 20 decks +10% synergy
Blood Artist
15% of 20 decks +3% synergy
Triskelion
14% of 28 decks +14% synergy
Park Heights Maverick
14% of 28 decks +14% synergy
Merfolk Skydiver
14% of 28 decks +13% synergy
Blighted Agent
14% of 28 decks +13% synergy
Fertilid
14% of 28 decks +12% synergy
Tendershoot Dryad
14% of 28 decks +12% synergy
Vorel of the Hull Clade
14% of 28 decks +11% synergy
Incubation Druid
14% of 28 decks +9% synergy
Forgotten Ancient
14% of 28 decks +8% synergy
Instants
Counterspell
36% of 28 decks -7% synergy
Atomize
33% of 12 decks +27% synergy
Prologue to Phyresis
32% of 28 decks +30% synergy
Beast Within
32% of 28 decks -6% synergy
Experimental Augury
29% of 28 decks +25% synergy
Ripples of Potential
29% of 21 decks +25% synergy
Inspiring Call
29% of 28 decks +21% synergy
Cyclonic Rift
29% of 28 decks +1% synergy
Nature's Claim
18% of 28 decks +8% synergy
Fierce Guardianship
18% of 28 decks -0% synergy
Heroic Intervention
18% of 28 decks -12% synergy
Radstorm
17% of 24 decks +15% synergy
Vraska's Fall
15% of 20 decks +12% synergy
Vampiric Tutor
15% of 20 decks -3% synergy
Infectious Bite
14% of 28 decks +12% synergy
Reality Shift
14% of 28 decks +5% synergy
Steady Progress
11% of 28 decks +10% synergy
Serum Snare
11% of 28 decks +9% synergy
Rapid Hybridization
11% of 28 decks +1% synergy
Pongify
11% of 28 decks -1% synergy
Worldly Tutor
11% of 28 decks -3% synergy
Mana Drain
11% of 28 decks -4% synergy
Sorceries
Unnatural Restoration
36% of 28 decks +32% synergy
Cultivate
32% of 28 decks -14% synergy
Drown in Ichor
30% of 20 decks +28% synergy
Farseek
29% of 28 decks -6% synergy
Demonic Tutor
25% of 20 decks +3% synergy
Kodama's Reach
25% of 28 decks -6% synergy
Nature's Lore
25% of 28 decks -7% synergy
Phyresis Outbreak
20% of 20 decks +18% synergy
Toxic Deluge
20% of 20 decks +3% synergy
Expand the Sphere
18% of 28 decks +16% synergy
Contentious Plan
18% of 28 decks +16% synergy
Thirsting Roots
18% of 28 decks +16% synergy
Rampant Growth
18% of 28 decks -17% synergy
Infectious Inquiry
15% of 20 decks +13% synergy
Diabolic Intent
15% of 20 decks +6% synergy
Triumph of the Hordes
14% of 28 decks +11% synergy
Smell Fear
11% of 28 decks +9% synergy
Croaking Counterpart
11% of 28 decks +9% synergy
Fabricate
11% of 28 decks +5% synergy
Three Visits
11% of 28 decks -14% synergy
Utility Artifacts
Skullclamp
32% of 28 decks +20% synergy
The Millennium Calendar
26% of 23 decks +25% synergy
Phyrexian Altar
25% of 28 decks +21% synergy
Tarrian's Soulcleaver
24% of 21 decks +22% synergy
Animation Module
21% of 28 decks +21% synergy
Thornbite Staff
18% of 28 decks +17% synergy
Contagion Engine
18% of 28 decks +17% synergy
Thousand-Year Elixir
18% of 28 decks +16% synergy
Lightning Greaves
18% of 28 decks -8% synergy
Swiftfoot Boots
18% of 28 decks -10% synergy
Ghost Lantern
15% of 20 decks +15% synergy
Altar of Dementia
14% of 28 decks +12% synergy
Darksteel Reactor
11% of 28 decks +11% synergy
Magistrate's Scepter
11% of 28 decks +10% synergy
Blade of the Bloodchief
11% of 28 decks +10% synergy
Contagion Clasp
11% of 28 decks +9% synergy
Mesmeric Orb
11% of 28 decks +9% synergy
Ichormoon Gauntlet
11% of 28 decks +9% synergy
Idol of Oblivion
11% of 28 decks +6% synergy
Enchantments
Doubling Season
36% of 28 decks +27% synergy
Inexorable Tide
32% of 28 decks +29% synergy
Mystic Remora
25% of 28 decks +7% synergy
Bastion of Remembrance
20% of 20 decks +14% synergy
Moldervine Reclamation
20% of 20 decks +11% synergy
Hardened Scales
18% of 28 decks +9% synergy
Necrosynthesis
15% of 20 decks +15% synergy
Black Market
15% of 20 decks +10% synergy
Binding the Old Gods
15% of 20 decks +9% synergy
Simic Ascendancy
14% of 28 decks +9% synergy
Parallel Lives
14% of 28 decks +7% synergy
Tribute to the World Tree
11% of 27 decks +3% synergy
Gutter Grime
11% of 28 decks +10% synergy
Jugan Defends the Temple
11% of 28 decks +10% synergy
Death's Presence
11% of 28 decks +10% synergy
Retreat to Coralhelm
11% of 28 decks +8% synergy
Primal Vigor
11% of 28 decks +8% synergy
Growing Rites of Itlimoc
11% of 28 decks +5% synergy
Wild Growth
11% of 28 decks -0% synergy
Rhystic Study
11% of 28 decks -17% synergy
Planeswalkers
Vraska, Golgari Queen
25% of 20 decks +22% synergy
Vraska, Betrayal's Sting
25% of 20 decks +22% synergy
Garruk, Cursed Huntsman
15% of 20 decks +13% synergy
Liliana, Dreadhorde General
15% of 20 decks +11% synergy
Kiora, Behemoth Beckoner
14% of 28 decks +11% synergy
Nissa, Voice of Zendikar
11% of 28 decks +10% synergy
Utility Lands
Yavimaya, Cradle of Growth
32% of 28 decks +23% synergy
Nesting Grounds
29% of 28 decks +27% synergy
Minamo, School at Water's Edge
25% of 28 decks +21% synergy
Reliquary Tower
25% of 28 decks -5% synergy
Bojuka Bog
25% of 20 decks -5% synergy
Hickory Woodlot
21% of 28 decks +21% synergy
Peat Bog
15% of 20 decks +15% synergy
Dreadship Reef
15% of 20 decks +14% synergy
Saprazzan Skerry
14% of 28 decks +14% synergy
Tyrite Sanctum
14% of 28 decks +12% synergy
Llanowar Reborn
14% of 28 decks +12% synergy
Mage-Ring Network
11% of 28 decks +10% synergy
Blast Zone
11% of 28 decks +9% synergy
Field of the Dead
11% of 28 decks +7% synergy
Dryad Arbor
11% of 28 decks +7% synergy
Oran-Rief, the Vastwood
11% of 28 decks +6% synergy
Urza's Saga
11% of 28 decks +4% synergy
Otawara, Soaring City
11% of 28 decks -6% synergy
Rogue's Passage
11% of 28 decks -9% synergy
Mana Artifacts
Sol Ring
71% of 28 decks -13% synergy
Arcane Signet
50% of 28 decks -22% synergy
Pentad Prism
18% of 28 decks +18% synergy
Staff of Compleation
18% of 28 decks +16% synergy
Midnight Clock
14% of 28 decks +9% synergy
Talisman of Curiosity
14% of 28 decks +2% synergy
Fellwar Stone
14% of 28 decks -7% synergy
Glistening Sphere
11% of 28 decks +9% synergy
Patriar's Seal
11% of 28 decks +9% synergy
Chromatic Lantern
11% of 28 decks +1% synergy
Simic Signet
11% of 28 decks -4% synergy
Lands
Command Tower
82% of 28 decks +8% synergy
Zagoth Triome
60% of 20 decks +29% synergy
Watery Grave
55% of 20 decks +14% synergy
Exotic Orchard
50% of 28 decks +14% synergy
Overgrown Tomb
50% of 20 decks +8% synergy
Yavimaya Coast
46% of 28 decks +20% synergy
Breeding Pool
46% of 28 decks +5% synergy
Llanowar Wastes
45% of 20 decks +19% synergy
Undergrowth Stadium
45% of 20 decks +19% synergy
Woodland Cemetery
45% of 20 decks +17% synergy
Hinterland Harbor
43% of 28 decks +15% synergy
Rejuvenating Springs
43% of 28 decks +14% synergy
Undercity Sewers
42% of 12 decks +28% synergy
Underground Mortuary
42% of 12 decks +25% synergy
Hedge Maze
39% of 18 decks +25% synergy
Morphic Pool
35% of 20 decks +9% synergy
Opulent Palace
35% of 20 decks +8% synergy
Verdant Catacombs
32% of 28 decks +21% synergy
Dreamroot Cascade
32% of 28 decks +13% synergy
Deathcap Glade
30% of 20 decks +16% synergy
Misty Rainforest
29% of 28 decks +17% synergy
Vivid Marsh
25% of 20 decks +24% synergy
Shipwreck Marsh
25% of 20 decks +6% synergy
Underground River
25% of 20 decks +5% synergy
Drowned Catacomb
25% of 20 decks -1% synergy
Sunken Hollow
25% of 20 decks -10% synergy
Polluted Delta
21% of 28 decks +10% synergy
Simic Growth Chamber
21% of 28 decks +2% synergy
Necroblossom Snarl
20% of 20 decks +8% synergy
Temple of Deceit
20% of 20 decks +4% synergy
Barkchannel Pathway
18% of 28 decks +9% synergy
Vineglimmer Snarl
18% of 28 decks +7% synergy
Blooming Marsh
15% of 20 decks +11% synergy
Bayou
15% of 20 decks +1% synergy
Underground Sea
15% of 20 decks +1% synergy
Temple of Malady
15% of 20 decks -1% synergy
Golgari Rot Farm
15% of 20 decks -3% synergy
Vivid Grove
14% of 28 decks +13% synergy
City of Brass
14% of 28 decks +6% synergy
Flooded Grove
14% of 28 decks +2% synergy
Temple of Mystery
14% of 28 decks -3% synergy
Evolving Wilds
14% of 28 decks -7% synergy
Mirrodin's Core
11% of 28 decks +11% synergy
Aether Hub
11% of 28 decks +10% synergy
Mirrex
11% of 28 decks +10% synergy
Vivid Creek
11% of 28 decks +10% synergy
Brokers Hideout
11% of 28 decks +9% synergy
Mana Confluence
11% of 28 decks +3% synergy
Waterlogged Grove
11% of 28 decks +3% synergy
Windswept Heath
11% of 28 decks +0% synergy