Confidence:StrongSolidPlausibleTentativeSpeculative

• Bloodline Recollector // Ancestral Craving

  1BB

  Creature — Vampire Warlock // InstantB

  Iron Mastiff can kill creatures (with damage or by shrinking them), enabling Bloodline Recollector's death-trigger or removal payoff.
• Chevill, Bane of Monsters

  BG

  Legendary Creature — Human RogueBG

  Iron Mastiff can kill creatures (with damage or by shrinking them), enabling Chevill, Bane of Monsters's death-trigger or removal payoff.
• Private Research

  U

  Enchantment — AuraU

  Iron Mastiff can kill creatures (with damage or by shrinking them), enabling Private Research's death-trigger or removal payoff.
• Quest for the Gravelord

  B

  EnchantmentB

  Iron Mastiff can kill creatures (with damage or by shrinking them), enabling Quest for the Gravelord's death-trigger or removal payoff.
• Bequeathal

  G

  Enchantment — AuraG

  Iron Mastiff can kill creatures (with damage or by shrinking them), enabling Bequeathal's death-trigger or removal payoff.
• Kraven the Hunter

  1BG

  Legendary Creature — Human Warrior VillainBG

  Iron Mastiff can kill creatures (with damage or by shrinking them), enabling Kraven the Hunter's death-trigger or removal payoff.
• Lagomos, Hand of Hatred

  1BR

  Legendary Creature — Human ShamanBR

  Iron Mastiff can kill creatures (with damage or by shrinking them), enabling Lagomos, Hand of Hatred's death-trigger or removal payoff.
• Enduring Renewal

  2WW

  EnchantmentW

  Iron Mastiff can kill creatures (with damage or by shrinking them), enabling Enduring Renewal's death-trigger or removal payoff.
• Isshin, Two Heavens as One

  RWB

  Legendary Creature — Human SamuraiBRW

  Isshin, Two Heavens as One makes Iron Mastiff's triggered ability trigger an additional time — each time it fires, you get it twice. Value, not a loop.
• Eater of Virtue

  1

  Legendary Artifact — EquipmentC

  Iron Mastiff can kill creatures (with damage or by shrinking them), enabling Eater of Virtue's death-trigger or removal payoff.
• Skullclamp

  1

  Artifact — EquipmentC

  Iron Mastiff can kill creatures (with damage or by shrinking them), enabling Skullclamp's death-trigger or removal payoff.
• Malicious Affliction

  BB

  InstantB

  Iron Mastiff can kill creatures (with damage or by shrinking them), enabling Malicious Affliction's death-trigger or removal payoff.
• Athreos, God of Passage

  1WB

  Legendary Enchantment Creature — GodBW

  Iron Mastiff can kill creatures (with damage or by shrinking them), enabling Athreos, God of Passage's death-trigger or removal payoff.
• Windcrag Siege

  1RW

  EnchantmentRW

  Windcrag Siege makes Iron Mastiff's triggered ability trigger an additional time — each time it fires, you get it twice. Value, not a loop.
• Emeritus of Woe // Demonic Tutor

  3B1B

  Creature — Vampire Warlock // SorceryB

  Iron Mastiff can kill creatures (with damage or by shrinking them), enabling Emeritus of Woe's death-trigger or removal payoff.
• Ob Nixilis, Unshackled

  4BB

  Legendary Creature — DemonB

  Iron Mastiff can kill creatures (with damage or by shrinking them), enabling Ob Nixilis, Unshackled's death-trigger or removal payoff.
• Glissa, the Traitor

  BGG

  Legendary Creature — Phyrexian Zombie ElfBG

  Iron Mastiff can kill creatures (with damage or by shrinking them), enabling Glissa, the Traitor's death-trigger or removal payoff.
• Incendiary

  R

  Enchantment — AuraR

  Iron Mastiff can kill creatures (with damage or by shrinking them), enabling Incendiary's death-trigger or removal payoff.
• The Meathook Massacre

  XBB

  Legendary EnchantmentB

  Iron Mastiff can kill creatures (with damage or by shrinking them), enabling The Meathook Massacre's death-trigger or removal payoff.
• Sticky Fingers

  R

  Enchantment — AuraR

  Iron Mastiff can kill creatures (with damage or by shrinking them), enabling Sticky Fingers's death-trigger or removal payoff.
• Assault Intercessor

  1WB

  Creature — Astartes WarriorBW

  Iron Mastiff can kill creatures (with damage or by shrinking them), enabling Assault Intercessor's death-trigger or removal payoff.
• Nurgle's Rot

  B

  Enchantment — AuraB

  Iron Mastiff can kill creatures (with damage or by shrinking them), enabling Nurgle's Rot's death-trigger or removal payoff.
• Barrensteppe Siege

  2WB

  EnchantmentBW

  Iron Mastiff can kill creatures (with damage or by shrinking them), enabling Barrensteppe Siege's death-trigger or removal payoff.
• Thijarian Witness

  1G

  Creature — Alien ClericG

  Iron Mastiff can kill creatures (with damage or by shrinking them), enabling Thijarian Witness's death-trigger or removal payoff.
• Sméagol, Helpful Guide

  1BG

  Legendary Creature — Halfling HorrorBG

  Iron Mastiff can kill creatures (with damage or by shrinking them), enabling Sméagol, Helpful Guide's death-trigger or removal payoff.