Confidence:StrongSolidPlausibleTentativeSpeculative

• Reanimate

  B

  SorceryB

  Reanimate puts Sea Serpent 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 Sea Serpent onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Liliana, Death's Majesty

  3BB

  Legendary Planeswalker — LilianaB

  Liliana, Death's Majesty puts Sea Serpent 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 Sea Serpent onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Sefris of the Hidden Ways

  WUB

  Legendary Creature — Human WizardBUW

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

  2B

  EnchantmentB

  Recurring Nightmare puts Sea Serpent onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Unfinished Business

  3WW

  SorceryW

  Unfinished Business puts Sea Serpent 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 Sea Serpent onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• The Cruelty of Gix

  3BB

  Enchantment — SagaB

  The Cruelty of Gix puts Sea Serpent onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Liliana, Waker of the Dead

  2BB

  Legendary Planeswalker — LilianaB

  Liliana, Waker of the Dead puts Sea Serpent onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Animate Dead

  1B

  Enchantment — AuraB

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

  1B

  SorceryB

  Exhume puts Sea Serpent onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Hell's Caretaker

  3B

  Creature — HorrorB

  Hell's Caretaker puts Sea Serpent onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Archpriest of Shadows

  3BB

  Creature — Human WarlockB

  Archpriest of Shadows puts Sea Serpent onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Life // Death

  G1B

  Sorcery // SorceryBG

  Life puts Sea Serpent onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Kardur's Vicious Return

  2BR

  Enchantment — SagaBR

  Kardur's Vicious Return puts Sea Serpent 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 Sea Serpent onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Meren of Clan Nel Toth

  2BG

  Legendary Creature — Human ShamanBG

  Meren of Clan Nel Toth puts Sea Serpent onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Victimize

  2B

  SorceryB

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

  1B

  SorceryB

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

  BB

  SorceryB

  Soul Exchange puts Sea Serpent onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Junji, the Midnight Sky

  3BB

  Legendary Creature — Dragon SpiritB

  Junji, the Midnight Sky puts Sea Serpent onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• From the Catacombs

  3BB

  SorceryB

  From the Catacombs puts Sea Serpent 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 Sea Serpent onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Rite of the Moth

  1WBB

  SorceryBW

  Rite of the Moth puts Sea Serpent onto the battlefield from a graveyard without casting it, so its mana cost is never paid.