Confidence:StrongSolidPlausibleTentativeSpeculative

• Reanimate

  B

  SorceryB

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

  1B

  Enchantment — AuraB

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

  1B

  SorceryB

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

  G1B

  Sorcery // SorceryBG

  Life puts Slithermuse 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 Slithermuse onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Persist

  1B

  SorceryB

  Persist puts Slithermuse onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Soul Exchange

  BB

  SorceryB

  Soul Exchange puts Slithermuse 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 Slithermuse onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Stinkweed Imp

  2B

  Creature — ImpB

  Slithermuse draws a large number of cards, enabling Stinkweed Imp's draw-payoff or weaponized-draw effect.
• Teysa Karlov

  2WB

  Legendary Creature — Human AdvisorBW

  Teysa Karlov makes Slithermuse's triggered ability trigger an additional time — each time it fires, you get it twice. Value, not a loop.
• Kid Loki

  U

  Legendary Creature — God Hero VillainU

  Slithermuse draws a large number of cards, enabling Kid Loki's draw-payoff or weaponized-draw effect.
• Toothy, Imaginary Friend

  3U

  Legendary Creature — IllusionU

  Slithermuse draws a large number of cards, enabling Toothy, Imaginary Friend's draw-payoff or weaponized-draw effect.
• Sefris of the Hidden Ways

  WUB

  Legendary Creature — Human WizardBUW

  Sefris of the Hidden Ways puts Slithermuse onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Red Ghost, Intangible Genius

  2UR

  Legendary Creature — Human Scientist VillainRU

  Slithermuse draws a large number of cards, enabling Red Ghost, Intangible Genius's draw-payoff or weaponized-draw effect.
• Recurring Nightmare

  2B

  EnchantmentB

  Recurring Nightmare puts Slithermuse onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Sheoldred, the Apocalypse

  2BB

  Legendary Creature — Phyrexian PraetorB

  Slithermuse draws a large number of cards, enabling Sheoldred, the Apocalypse's draw-payoff or weaponized-draw effect.
• Niv-Mizzet, Parun

  UUURRR

  Legendary Creature — Dragon WizardRU

  Slithermuse draws a large number of cards, enabling Niv-Mizzet, Parun's draw-payoff or weaponized-draw effect.
• Ob Nixilis Reignited

  3BB

  Legendary Planeswalker — NixilisB

  Slithermuse draws a large number of cards, enabling Ob Nixilis Reignited's draw-payoff or weaponized-draw effect.
• Teferi, Hero of Dominaria

  3WU

  Legendary Planeswalker — TeferiUW

  Slithermuse draws a large number of cards, enabling Teferi, Hero of Dominaria's draw-payoff or weaponized-draw effect.
• Jolrael, Mwonvuli Recluse

  1G

  Legendary Creature — Human DruidG

  Slithermuse draws a large number of cards, enabling Jolrael, Mwonvuli Recluse's draw-payoff or weaponized-draw effect.
• Necroplasm

  1BB

  Creature — OozeB

  Slithermuse draws a large number of cards, enabling Necroplasm's draw-payoff or weaponized-draw effect.
• Mischievous Mystic

  1U

  Creature — Human WizardU

  Slithermuse draws a large number of cards, enabling Mischievous Mystic's draw-payoff or weaponized-draw effect.
• Drivnod, Carnage Dominus

  3BB

  Legendary Creature — Phyrexian HorrorB

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