Marrow-Gnawer Commander Deck Guide

Marrow-Gnawer | Illustration by Wayne Reynolds

Sometime around 10 years ago, my family and I noticed that some food packages in our pantry were broken. Then we checked our pasta bags, and some of those were broken and seemed like they’d been gnawed on. Turns out we had a rat living in our kitchen and stealing our food. We eventually saw the rat, and boy was it big.

I obviously named the little guy “Bart,” because I’m so funny. If there’s one thing we learned from that experience, it was that rats are absurdly resilient creatures. No matter what traps we placed and how we tried to get rid of it, it just wouldn’t die nor leave. I think it took somewhere around six to nine months for it to actually go away, and we all assume it just took off because we stopped storing food where it lived. We never found a body or anything.

Rats have shown up in almost every set and plane in Magic’s history, not unlike how they can be found in most parts of the world, especially those inhabited by humans. But there’s only one plane in the multiverse where rats aren’t just simple, four-legged vermin: Kamigawa. The nezumi (literally translated from Japanese as “rat-folk”) of Kamigawa are the only rat creatures in the multiverse who are anthropomorphic and possess a human-like level of intelligence.

Today I have a deck for you built around Marrow-Gnawer, one of old Kamigawa’s most important nezumi. He literally killed his way up the steps of his original gang, helped Toshiro Umezawa, and joined the Hyozan Reckoners. Let’s get into it!

The Deck

Ink-Eyes, Servant of Oni (Secret Lair) | Illustration by JungShan

The Commander

Marrow-Gnawer’s abilities represent some aspects of his story. He managed to lead his gang of Nezumi, but he also got that place by killing his way to the top. This card lets you do essentially that: amass a huge army of rats and making them harder to block. This obviously means this is a very focused rat tribal.

One of the best things about this commander is that there’s tons of ways to create rat tokens and have them swarm the battlefield. That gives you a ton of strategically un-important targets to sacrifice and a way to ensure each sacrifice yields a ton of new creatures each time.

Ratcallers

Chittering Witch, Ogre Slumlord, and Piper of the Swarm all serve to keep your swarm of tokens strong and ever growing so that your commander’s ability creates massive armies with each activation.

Chittering Witch and Piper of the Swarm also bring some additional value by letting you take even more advantage of your large numbers of rats.

On the other hand, you also have Ratcatcher. This card won’t fill up your token army, but it allows you to cheat your utility rats into your hand.

Tribal Powers

The deck runs plenty of “generic” tribal tools: Adaptive Automaton, Metallic Mimic, Coat of Arms, etc. These are all staples for any tribal deck and enable you to carry out some nasty attacks without fearing for your creatures.

You also have Ashcoat of the Shadow Swarm and Karumonix, the Rat King (the only legendary rat who isn’t from Kamigawa). These two creatures have abilities that benefit rats specifically, making them a threat to be reckoned with. Karumonix specifically can be a huge wincon if your swarm is large enough to hit each of your opponents with 10 or more creatures.

Graveyard Recursion

There’s a lot of cards in this deck that can return creatures from your graveyard to your hand or battlefield. Considering you’ll be sacrificing creatures with your commander pretty often, you need to make sure there’s ways to recover them if you happen to have to sacrifice any non-tokens.

Wincons

I’ve already mentioned Karumonix, the Rat King as a possible wincon (besides good old direct damage). Giving toxic 1 to all your rats means you simply need to hit an opponent with 10 creatures to eliminate them. With an ever growing, massive swarm of rat tokens, this shouldn’t be that hard.

Altar of the Brood can serve as another pretty reliable wincon by grinding your opponents’ decks away with each permanent that enters the battlefield under your control. Your commander’s ability can even get you dozens of creature tokens in a single turn, which in turn obliterates your opponents’ decks.

Along with this card there’s also Ayara, First of Locthwain which also grinds down your opponents’ life points for each permanent that enters your field.

Another alternative is pairing Ashnod's Altar with Zulaport Cutthroat or Bastion of Remembrance and your massive numbers of rats, sacrificing them away to harm your opponents.

Gruesome Fate also depends on you having a ton of creatures on the field, but it can end a game with a single spell. And the flavor text is from a character nicknamed “Ratty,” so it earns some flavor points.

The Mana Base

The largest part of the mana in this deck is good old basic swamps. This’ll help if you choose to cast Contamination since it’ll most likely hinder your opponents, but it won’t really harm you much. I also added Cabal Coffers for the obvious advantage it gets from this many swamps, and Urborg, Tomb of Yawgmoth for good measure.

Castle Locthwain, Path of Ancestry, Barren Moor, and Witch's Cottage all have added utility to make the most out of your mana base.

Nykthos, Shrine to Nyx can yield huge amounts of mana with the right field, and yours should consistently have quite a lot of devotion to black.

The Strategy

Most of this deck is pretty straightforward: play a ton of rats, give those rats advantages or additional power, then use your rats to take out your opponents. Your commander ensures you have more and more rats each turn while giving them much needed evasion.

There are other creatures and artifacts that also give your swarm +1/+1 counters, additional power, evasive skills, and other ways to ensure that you can put some pressure on your opponents. You also have cards to return creatures from your graveyard to your hand, ensuring that any non-token rats you sacrifice can keep coming back.

Combos and Interactions

While I made sure to place enough synergies into the deck, there’s only one proper combo, which can go infinite: Marrow-Gnawer and Thornbite Staff. These two cards alone (and at least two other rats on the field) can net you infinite rat tokens. This also means infinite ETB and LTB triggers.

This obviously means you’ll have to keep in mind that your playgroup might not like this, so check with them before dropping it on them.

Another possible rule 0 breaker might be Gruesome Fate. While the other possible wincons are also pretty low on interactions (like using Ashnod's Altar to sacrifice absurd numbers of rats to trigger Zulaport Cutthroat), they can at least be reasonably telegraphed before you unleash them. Gruesome Fate can come completely out of nowhere and ends the game on the spot if no one has any way to respond to it. Be sure to check that the other players are okay with it.

Budget Options

Most rats aren’t all that great, which means that most of the most powerful ones are already in this deck. Cards like Ashcoat of the Shadow Swarm and Ink-Eyes, Servant of Oni can simply be replaced by more inexpensive rats, but that’ll also mean lowering the power level of the deck.

Then we have the buffing artifacts that are harder to properly replace. Most of them, like Coat of Arms or Door of Destinies, all cost over 10$ and are pretty hard to replace, especially in monoblack decks. Icon of Ancestry can at least grant you a small boon while also allowing you to find rats in the top cards of your library. Obelisk of Urd not only buffs your creatures, but you can also use your rat tokens to cast it, which gives it an extra benefit when replacing other cards in the deck. Hall of Triumph and Bad Moon are also pretty good and they’ll also make your non-rat black creatures stronger.

Kindred Dominance can be replaced with In Garruk's Wake. It may be harder to cast but overall serves the same function.

Other Builds

There’s another, very popular, build for Marrow-Gnawer: a full Rat Colony deck. This build essentially replaces most of the creatures in your deck with as many copies of Rat Colony as you want to include.

This deck gets support from a handful of cards like Secret Salvage and Mirror Box. The most important card for this build is Thrumming Stone. If you play it right, you can play all your Rat Colony cards without paying their mana costs, which can quickly overwhelm your opponents if they don’t have any board wipes yet.

Wrap Up

Pack Rat (Return to Ravnica) | Illustration by Kev Walker

I love rats. They’re adorable and super weird. I also really like how they’re represented through the nezumi of Kamigawa, and Marrow-Gnawer is a pretty good card at that. I built this deck to be relatively strong, but I kept it mostly focused on being fun and original. I hope we’ll eventually get some more support for rats as a tribe, always without risking their identity as creatures.

But enough about me. Did you like the decklist? Would you have built it any different? Did I miss any must-have rats? Feel free to let me know, and meanwhile don’t forget to join the Draftsim Discord where you’ll find an amazing community of MTG fans.

That’s enough from me for now. Have a good one, and I’ll see you next time!