Mono-black Rat tribal that floods the board with Rats and turns every one of them into a poison source through Karumonix, the Rat King, which grants toxic 1 to all other Rats. The deck pairs wide token generation and anthem effects with evasion such as fear, menace and shadow so many small Rats connect each turn. A proliferate package and direct poison spells push opponents toward ten counters faster than combat alone. Karumonix's enter trigger, tutors and upkeep Rat-fetchers keep the creature count high, while sacrifice outlets and death triggers turn spare bodies into cards and more tokens. How it wins: Swing with a wide, evasive Rat swarm where each Rat adds a poison counter, then proliferate and use poison spells to finish players off, with pumped Rat combat damage as a backup kill. Key roles: - Rat swarm generation: Repeatable token makers and Rats that multiply themselves build the wide board Karumonix, the Rat King turns into many toxic hits per combat (Lord Skitter, Sewer King, Marrow-Gnawer, Pack Rat). - Evasion and anthems: Granting unblockability-style keywords and scaling power per Rat lets the swarm connect and become a lethal damage threat on its own (Piper of the Swarm, Cover of Darkness, Ashcoat of the Shadow Swarm). - Poison and proliferate: Infect creatures, poison-granting spells and proliferate effects stack counters beyond combat and also grow -1/-1 counters on enemy creatures (Vraska, Betrayal's Sting, Grim Affliction, Septic Rats). - Rat card advantage and tutoring: Karumonix's enter trigger, upkeep fetchers and graveyard recursion keep a steady supply of Rats in hand and on the battlefield (Ratcatcher, Herald's Horn, Ashcoat of the Shadow Swarm). - Sacrifice and death value: Expendable tokens feed draw outlets and death triggers that refill the hand or make more Rats, and mass recursion rebuilds after wipes (Skullclamp, Ogre Slumlord, Patriarch's Bidding). - Rat-friendly board control: One-sided sweepers that spare Rats or punish poisoned players clear blockers ahead of the swarm (Crippling Fear, Phyresis Outbreak, Crypt Rats).

Karumonix, the Rat King decklist

• Arcane Signet
• Bontu's Monument
• Contagion Clasp
• Glistening Sphere
• Herald's Horn
• Jet Medallion
• Patchwork Banner
• Skullclamp
• Sol Ring
• Bojuka Bog
• Cabal Coffers
• Karn's Bastion
• Mudflat Village
• Nykthos, Shrine to Nyx
• Path of Ancestry
• Rogue's Passage
• 24× Swamp
• Swarmyard
• Urborg, Tomb of Yawgmoth
• Witch's Cottage
• Ashcoat of the Shadow Swarm
• Blightbelly Rat
• Burglar Rat
• Crypt Rats
• Ichor Rats
• Lord Skitter's Butcher
• Lord Skitter, Sewer King
• Marrow-Gnawer
• Nezumi Informant
• Ogre Slumlord
• Pack Rat
• Persistent Marshstalker
• Piper of the Swarm
• Rancid Rats
• 13× Rat Colony
• Ratcatcher
• Septic Rats
• Stronghold Rats
• Tangled Colony
• Typhoid Rats
• Voracious Vermin
• Black Market Connections
• Cover of Darkness
• Necrogen Communion
• Phyrexian Arena
• Dark Ritual
• Deadly Dispute
• Go for the Throat
• Grim Affliction
• Rat Out
• Vampiric Tutor
• Village Rites
• Vraska's Fall
• Whisper of the Dross
• Vraska, Betrayal's Sting
• Crippling Fear
• Demonic Tutor
• Drown in Ichor
• Infectious Inquiry
• Patriarch's Bidding
• Phyresis Outbreak
• Swamp
• Swamp
• Swamp