Confidence:StrongSolidPlausibleTentativeSpeculative

• Reanimate

  B

  SorceryB

  Reanimate puts Grothama, All-Devouring 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 Grothama, All-Devouring 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 Grothama, All-Devouring onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Animate Dead

  1B

  Enchantment — AuraB

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

  1B

  SorceryB

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

  G1B

  Sorcery // SorceryBG

  Life puts Grothama, All-Devouring 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 Grothama, All-Devouring onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Soul Exchange

  BB

  SorceryB

  Soul Exchange puts Grothama, All-Devouring 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 Grothama, All-Devouring onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Faerie Mastermind

  1U

  Creature — Faerie RogueU

  Grothama, All-Devouring draws a large number of cards, enabling Faerie Mastermind's draw-payoff or weaponized-draw effect.
• Yore-Tiller Nephilim

  WUBR

  Creature — NephilimBRUW

  Yore-Tiller Nephilim puts Grothama, All-Devouring onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Teysa Karlov

  2WB

  Legendary Creature — Human AdvisorBW

  Teysa Karlov makes Grothama, All-Devouring's triggered ability trigger an additional time — each time it fires, you get it twice. Value, not a loop.
• Sefris of the Hidden Ways

  WUB

  Legendary Creature — Human WizardBUW

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

  2B

  EnchantmentB

  Recurring Nightmare puts Grothama, All-Devouring onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• The Unagi of Kyoshi Island

  3UU

  Legendary Creature — SerpentU

  Grothama, All-Devouring draws a large number of cards, enabling The Unagi of Kyoshi Island's draw-payoff or weaponized-draw effect.
• Liliana, Waker of the Dead

  2BB

  Legendary Planeswalker — LilianaB

  Liliana, Waker of the Dead puts Grothama, All-Devouring onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Ob Nixilis Reignited

  3BB

  Legendary Planeswalker — NixilisB

  Grothama, All-Devouring draws a large number of cards, enabling Ob Nixilis Reignited's draw-payoff or weaponized-draw effect.
• Notion Thief

  2UB

  Creature — Human RogueBU

  Grothama, All-Devouring draws a large number of cards, enabling Notion Thief's draw-payoff or weaponized-draw effect.
• Hell's Caretaker

  3B

  Creature — HorrorB

  Hell's Caretaker puts Grothama, All-Devouring onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Defacing Duskmage // Vandal's Edit

  WB1WB

  Creature — Dog Warlock // InstantBW

  Grothama, All-Devouring draws a large number of cards, enabling Defacing Duskmage's draw-payoff or weaponized-draw effect.
• Gandalf the White

  3WW

  Legendary Creature — Avatar WizardW

  Gandalf the White makes Grothama, All-Devouring's triggered ability trigger an additional time — each time it fires, you get it twice. Value, not a loop.
• Kardur's Vicious Return

  2BR

  Enchantment — SagaBR

  Kardur's Vicious Return puts Grothama, All-Devouring onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Godo, Bandit Warlord

  5R

  Legendary Creature — Human BarbarianR

  Godo, Bandit Warlord grants an extra combat phase, enabling Grothama, All-Devouring's combat-trigger payoff.
• Meren of Clan Nel Toth

  2BG

  Legendary Creature — Human ShamanBG

  Meren of Clan Nel Toth puts Grothama, All-Devouring onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Drivnod, Carnage Dominus

  3BB

  Legendary Creature — Phyrexian HorrorB

  Drivnod, Carnage Dominus makes Grothama, All-Devouring's triggered ability trigger an additional time — each time it fires, you get it twice. Value, not a loop.