Confidence:StrongSolidPlausibleTentativeSpeculative

• Novablast Wurm

  3GGWW

  Creature — WurmGW

  Novablast Wurm wipes or mass-sacrifices creatures, and Undying Beast profits when creatures die — or comes back from the wipe itself.
• Grim Giganotosaurus

  5BG

  Creature — DinosaurBG

  Grim Giganotosaurus wipes or mass-sacrifices creatures, and Undying Beast profits when creatures die — or comes back from the wipe itself.
• Bolas's Citadel

  3BBB

  Legendary ArtifactB

  Bolas's Citadel is a sacrifice outlet, enabling Undying Beast's death or sacrifice trigger.
• Necrotic Hex

  6B

  SorceryB

  Necrotic Hex wipes or mass-sacrifices creatures, and Undying Beast profits when creatures die — or comes back from the wipe itself.
• My Precious // Allure of Power

  31B

  Legendary Artifact — Equipment // Instant — AdventureB

  My Precious is a sacrifice outlet, enabling Undying Beast's death or sacrifice trigger.
• Reanimate

  B

  SorceryB

  Reanimate puts Undying Beast onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Grimgrin, Corpse-Born

  3UB

  Legendary Creature — Zombie WarriorBU

  Grimgrin, Corpse-Born is a sacrifice outlet, enabling Undying Beast's death or sacrifice trigger.
• Cataclysm

  2WW

  SorceryW

  Cataclysm wipes or mass-sacrifices creatures, and Undying Beast profits when creatures die — or comes back from the wipe itself.
• Fiend Artisan

  B/GB/G

  Creature — NightmareBG

  Fiend Artisan is a sacrifice outlet, enabling Undying Beast's death or sacrifice trigger.
• Ob Nixilis of the Black Oath

  3BB

  Legendary Planeswalker — NixilisB

  Ob Nixilis of the Black Oath is a sacrifice outlet, enabling Undying Beast's death or sacrifice trigger.
• Grave Researcher // Reanimate

  2BB

  Creature — Troll Warlock // SorceryB

  Grave Researcher puts Undying Beast onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Zimone and Dina

  BGU

  Legendary Creature — Human DryadBGU

  Zimone and Dina is a sacrifice outlet, enabling Undying Beast's death or sacrifice trigger.
• The Eternal Wanderer

  4WW

  Legendary PlaneswalkerW

  The Eternal Wanderer wipes or mass-sacrifices creatures, and Undying Beast profits when creatures die — or comes back from the wipe itself.
• Magus of the Disk

  2WW

  Creature — Human WizardW

  Magus of the Disk wipes or mass-sacrifices creatures, and Undying Beast profits when creatures die — or comes back from the wipe itself.
• The Night of the Doctor

  4WW

  Enchantment — SagaW

  The Night of the Doctor wipes or mass-sacrifices creatures, and Undying Beast profits when creatures die — or comes back from the wipe itself.
• Garruk Relentless // Garruk, the Veil-Cursed

  3G

  Legendary Planeswalker — Garruk // Legendary Planeswalker — GarrukBG

  Garruk Relentless is a sacrifice outlet, enabling Undying Beast's death or sacrifice trigger.
• Liliana, Dreadhorde General

  4BB

  Legendary Planeswalker — LilianaB

  Liliana, Dreadhorde General wipes or mass-sacrifices creatures, and Undying Beast profits when creatures die — or comes back from the wipe itself.
• Teysa Karlov

  2WB

  Legendary Creature — Human AdvisorBW

  Teysa Karlov makes Undying Beast's triggered ability trigger an additional time — each time it fires, you get it twice. Value, not a loop.
• The Rise of Sozin // Fire Lord Sozin

  4BB

  Enchantment — Saga // Legendary Creature — Human NobleB

  The Rise of Sozin wipes or mass-sacrifices creatures, and Undying Beast profits when creatures die — or comes back from the wipe itself.
• Planar Collapse

  1W

  EnchantmentW

  Planar Collapse wipes or mass-sacrifices creatures, and Undying Beast profits when creatures die — or comes back from the wipe itself.
• Wight of the Reliquary

  BG

  Creature — Zombie KnightBG

  Wight of the Reliquary is a sacrifice outlet, enabling Undying Beast's death or sacrifice trigger.
• Amalia Benavides Aguirre

  WB

  Legendary Creature — Vampire ScoutBW

  Amalia Benavides Aguirre wipes or mass-sacrifices creatures, and Undying Beast profits when creatures die — or comes back from the wipe itself.
• Sefris of the Hidden Ways

  WUB

  Legendary Creature — Human WizardBUW

  Sefris of the Hidden Ways puts Undying Beast onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• The Phasing of Zhalfir

  2UU

  Enchantment — SagaU

  The Phasing of Zhalfir wipes or mass-sacrifices creatures, and Undying Beast profits when creatures die — or comes back from the wipe itself.
• Slaughter the Strong

  1WW

  SorceryW

  Slaughter the Strong wipes or mass-sacrifices creatures, and Undying Beast profits when creatures die — or comes back from the wipe itself.