Confidence:StrongSolidPlausibleTentativeSpeculative

• Reanimate

  B

  SorceryB

  Reanimate puts Koma, World-Eater onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Grave Researcher // Reanimate

  2BB

  Creature — Troll Warlock // SorceryB

  Grave Researcher puts Koma, World-Eater onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Koma, Cosmos Serpent

  3GGUU

  Legendary Creature — SerpentGU

  Both cards produce the same kind of effect (shared token subtype).
• Sefris of the Hidden Ways

  WUB

  Legendary Creature — Human WizardBUW

  Sefris of the Hidden Ways puts Koma, World-Eater onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Recurring Nightmare

  2B

  EnchantmentB

  Recurring Nightmare puts Koma, World-Eater onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Priest of Fell Rites

  WB

  Creature — Human WarlockBW

  Priest of Fell Rites puts Koma, World-Eater onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Animate Dead

  1B

  Enchantment — AuraB

  Animate Dead puts Koma, World-Eater onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Exhume

  1B

  SorceryB

  Exhume puts Koma, World-Eater onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Life // Death

  G1B

  Sorcery // SorceryBG

  Life puts Koma, World-Eater onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Dance of the Dead

  1B

  Enchantment — AuraB

  Dance of the Dead puts Koma, World-Eater onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Victimize

  2B

  SorceryB

  Victimize puts Koma, World-Eater onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Soul Exchange

  BB

  SorceryB

  Soul Exchange puts Koma, World-Eater onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Ascent of the Worthy

  1WB

  Enchantment — SagaBW

  Ascent of the Worthy puts Koma, World-Eater onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Necromancy

  2B

  EnchantmentB

  Necromancy puts Koma, World-Eater onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Loyal Retainers

  2W

  Creature — Human AdvisorW

  Loyal Retainers puts Koma, World-Eater onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Karai, Future of the Foot

  1WB

  Legendary Creature — Human NinjaBW

  Karai, Future of the Foot puts Koma, World-Eater onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• One Last Job

  2W

  SorceryW

  One Last Job puts Koma, World-Eater onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Rat King, Verminister

  1B

  Legendary Creature — Rat AvatarB

  Rat King, Verminister puts Koma, World-Eater onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• The Falcon, Airship Restored

  2B

  Legendary Artifact — VehicleB

  The Falcon, Airship Restored puts Koma, World-Eater onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Reincarnation

  1GG

  InstantG

  Reincarnation puts Koma, World-Eater onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Pulsemage Advocate

  2W

  Creature — Human ClericW

  Pulsemage Advocate puts Koma, World-Eater onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Archivist of Gondor

  2U

  Creature — Human AdvisorU

  Both cards trigger on damage dealt — they fire together.
• Sygg, Wanderwine Wisdom // Sygg, Wanderbrine Shield

  1U

  Legendary Creature — Merfolk Wizard // Legendary Creature — Merfolk RogueUW

  Both cards trigger on damage dealt — they fire together.
• Liliana, Death's Majesty

  3BB

  Legendary Planeswalker — LilianaB

  Liliana, Death's Majesty puts Koma, World-Eater onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Yore-Tiller Nephilim

  WUBR

  Creature — NephilimBRUW

  Yore-Tiller Nephilim puts Koma, World-Eater onto the battlefield from a graveyard without casting it, so its mana cost is never paid.