Confidence:StrongSolidPlausibleTentativeSpeculative

• Lord Skitter, Sewer King

  2B

  Legendary Creature — Rat NobleB

  Both cards produce the same kind of effect (shared token subtype).
• Piper of the Swarm

  1B

  Creature — Human WarlockB

  Both cards produce the same kind of effect (shared token subtype).
• Totentanz, Swarm Piper

  1BR

  Legendary Creature — Human Warlock BardBR

  Both cards produce the same kind of effect (shared token subtype).
• Ogre Slumlord

  3BB

  Creature — Ogre RogueB

  Both cards produce the same kind of effect (shared token subtype).
• Rat King, Verminister

  1B

  Legendary Creature — Rat AvatarB

  Both cards produce the same kind of effect (shared token subtype).
• Marrow-Gnawer

  3BB

  Legendary Creature — Rat RogueB

  Both cards produce the same kind of effect (shared token subtype).
• Reanimate

  B

  SorceryB

  Reanimate puts Rat King, Pale Piper 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 Rat King, Pale Piper 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 Rat King, Pale Piper's triggered ability trigger an additional time — each time it fires, you get it twice. Value, not a loop.
• Harried Spearguard

  R

  Creature — Human SoldierR

  Both cards produce the same kind of effect (shared token subtype).
• Priest of Fell Rites

  WB

  Creature — Human WarlockBW

  Priest of Fell Rites puts Rat King, Pale Piper onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Genku, Future Shaper

  2WU

  Legendary Creature — Moonfolk WizardUW

  Both cards produce the same kind of effect (shared token subtype).
• Vren, the Relentless

  2UB

  Legendary Creature — Rat RogueBU

  Both cards produce the same kind of effect (shared token subtype).
• Animate Dead

  1B

  Enchantment — AuraB

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

  1B

  SorceryB

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

  G1B

  Sorcery // SorceryBG

  Life puts Rat King, Pale Piper 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 Rat King, Pale Piper 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 Rat King, Pale Piper's triggered ability trigger an additional time — each time it fires, you get it twice. Value, not a loop.
• Soul Exchange

  BB

  SorceryB

  Soul Exchange puts Rat King, Pale Piper onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Ogre Chitterlord

  4RR

  Creature — Ogre WarriorR

  Both cards produce the same kind of effect (shared token subtype).
• Redcap Gutter-Dweller

  2RR

  Creature — Goblin WarriorR

  Both cards produce the same kind of effect (shared token subtype).
• Annie Joins Up

  1RGW

  Legendary EnchantmentGRW

  Annie Joins Up makes Rat King, Pale Piper's triggered ability trigger an additional time — each time it fires, you get it twice. Value, not a loop.
• Roaming Throne

  4

  Artifact Creature — GolemC

  Roaming Throne makes Rat King, Pale Piper's triggered ability trigger an additional time — each time it fires, you get it twice. Value, not a loop.
• Ruthless Radrat

  1BB

  Creature — Rat MutantB

  Both cards produce the same kind of effect (shared token subtype).
• Tangled Colony

  1B

  Creature — RatB

  Both cards produce the same kind of effect (shared token subtype).