This is my Marrow deck, and I've had a blast playing with it. Heres what it has going on:

Cheap/Free Rats

-  Thrumming Stone: Do you need a lot of rats on the field at one time? Do all of them just so happen to have the same name? Here it is. This alone can win the game, but it's also a good answer to the kid playing Wrath of God every couple turns.

-  Jet Medallion & Locket of Yesterdays: Making Rat Colony 1 black mana is very helpful, dump your hand, refill with Necropotence.

Protection

This isn't a huge issue, because you don't NEED Marrow to win. But having Lightning Greaves and Swiftfoot Boots in the deck can help him stay around. Also give a new fat rat the right to swing without summoning sickness.

Draw

-  Necropotence: Nothing needs explainded here, fill your hand drop your rats, fetch Whip of Erebos if your worried about your life total.

-  Skullclamp: 1 mana, 1 sac, 2 draw. Grave Pact on the field makes this better. Worried about losing your rats? Fetch Oversold Cemetery for some card advantage. Or go whole hog if things aren't going right and grab Living Death.

-  Dark Prophecy: Phyrexian Arena everytime one of your rats die. Just be careful, this can be a huge help or a curse. Fetch Whip of Erebos again if you think it'll be an issue.

-  Phyrexian Arena & Underworld Connections: Consistent card draw.

-  Vampiric Rites: Draw, life gain, and a sac trigger for some of your oher cards.

-  Dark Tutelage: A newer addition to this deck for me. The worst amount of damage you'd take would be 5. 2 life for a rat is what you'll mostly see though.

Boosts

-  Coat of Arms: A win condition. Takes your rats and makes 'em MASSIVE THREATS.

-  Door of Destinies: A bit slower than Coat, but Thrumming Stone helps this one get going faster.

-  Ogre Slumlord: Gives your Rat Colony another shot at life, while also being a nasty deathtoucher still. Rat tokens still count on colonys, so he keeps the team strong for a bit longer.

-  Pack Rat: Just a great rat, also making big tokens can be worth it in some situations.

Tutor/Flex

Tutor and Flex. I keep this an open flex spot sense more or better win conditions can fit here. But, with the deck being a swarm of the same rat, you NEED ways to find answers and win conditions. It's hard to stubble into the one you need that particular match.

Demonic Tutor  Vampiric Tutor  Diabolic Intent  Beseech the Queen  Diabolic Tutor  Mastermind's Acquisition  Demonic Collusion  Dark Petition  Brainspoil (Most win cons are 5 drops, so you'd transmute with this)

Answers / Win

-  Grave Pact & Dictate of Erebos: These guys control the board so well for us. Another rat died on my field, sac your Vorinclex, Voice of Hunger please. Thank you. These paired with a sac outlet like Altar of Dementia or Vampiric Rites and you got a good field sweep anytime ya need it.

-  Altar of Dementia: This breaks up stalemates, if someone is rocking a Crawlspace, just make super fat rats and mill them to death. It works.

-  Whip of Erebos: if the game starts getting long and drawn out, you'll probably end up needing this. Lots of things in the deck require our life, but hitting the enemy with 6 7/1s can really fix that in a hurry.

-  Secret Salvage: Sets up two different win combos. Mortal Combat, grab all your rats with salvage, discard down to 7 on your end step. If you see your next turn and the rats are still in the grave, you win. Or salvage and discard like you did before, and then Living Death an army onto the field.

-  Cover of Darkness: If Marrow died too much but you still need a Fear win condition.

-  Oversold Cemetery: card advantage, works great with Thrumming Stone. Reusing the dead rats to keep them rippling from the deck.

-  Hatred: Marrow has fear baked in, swing in for the commander damage kill with just a bit of your life as payment.



I hope you guys liked this, let me know what you would change up or add in. The deck is always evolving and getting better.

Love ya guys.