Muldrotha - Reanimator & Card Draw (EDH / Commander)

Can theoretically work even if you switch Muldrotha for any other legendary sultai creature in the 99. [Tasigur, the Golden Fang can be used as the commander if your prefer to build him in a non-combo way, but I would add in a lot of cantrips such as Ponder, Brainstorm & Preordain while also replacing a good chunk of permanents in the deck with instant speed spells with the same function. Reusable ramp should be replaced by mana rocks, as those do not enter your graveyard, thus reducing the amount of "undesirable" cards in there for Tasigur's activated ability.]

Cards like Secrets of the Dead & River Kelpie feel like unnecessary win-more cards, but they might be useful in this iteration, since there are a numerous ways to recur from the grave.
Gravebreaker Lamia party fits into this category as well. She competes with Corpse Connoisseur, who can unearth himself without having to rely on Muldrotha.

I did forego "classic" green ramp options such as Cultivate and Kodama's Reach and instead favored Dreamscape Artist, Harrow & Springbloom Druid, all of which fill my graveyard with lands while pulling two basic lands from my deck. They were not put in with the intent to provide fodder for Muldrotha; they were instead added due to the inclusion of The Gitrog Monster, Tatyova, Benthic Druid, Avenger of Zendikar & Hedron Crab. Terramorphic Expanse, Evolving Wilds & Crop Rotation fill a similar role. I don't think I will be keeping any of the sacrifice based ramp cards if I end up cutting a large portion of the potential pay-offs, the slow fetch lands would be replaced by scry duals as well.

Removal options have been spread over as many different permanent types as possible. In general, permanent based cards were mostly preferred over their sorcery / instant alternatives. This does however raise your average cmc and severely reduces your ability to interact on the stack.

Functionally similar cards:

• Shriekmaw, Gilt-Leaf Winnower, Ravenous Chupacabra & Noxious Gearhulk compete for the same creature-based removal slot, the latter two options have no downside at the cost of a higher cmc, while the former card does not require a sacrifice outlet to be used repeatedly.
• Caustic Caterpillar, Thrashing Brontodon, Reclamation Sage & Manglehorn compete for the same slot. Caustic Caterpillar was chosen since it is a potential turn 1 play and due to its instant speed interaction, which this deck lacks.
• Viscera Seer and Woe Strider fill the same role. The former has the advantage of a much lower cmc, while the latter does not rely on Muldrotha being in play. Any of those two cards along with Muldrotha and Kaya's Ghostform in play essentially read: "B: Scry 1".
• High Market, Altar of Dementia, Ashnod's Altar, Phyrexian Altar & Yawgmoth, Thran Physician are other free sacrifice outlets to choose from to evade exiling effects.
• Perpetual Timepiece, Elixir of Immortality & Loaming Shaman protect your graveyard. The former two can be used at instant speed while Loaming Shaman can double as graveyard hate.
• Baleful Strix, Mulldrifter, Coiling Oracle, Urza's Bauble, Mishra's Bauble & Ice-Fang Coatl try to replace the usual 1 cmc instant speed cantrips.

Possible changes & additions:

• Lord of Extinction & Jarad, Golgari Lich Lord --> Syr Konrad (synergy with Living Death) & Rune-Scarred Demon
• Artifact based ramp --> more green-based land ramp?
• Risen Reef + lots of elementals like Baleful Force, Mulldrifter, Shriekmaw, Night Incarnate
• Kederekt Leviathan is essentially a two cmc board wipe along with Animate Dead or Dance of the Dead, though its inclusion would make casting Living Death undesirable (Massacre Girl also suffers from that undesirable interaction).
• Final Parting along with Animate Dead / Dance of the Dead / Necromancy tutors any creature card from your deck to the field.
• Elephant Grass, Spore Frog & Spike Weaver are probably the best pillow fort cards available to Muldrotha.
• Zur's Weirding is a powerful addition that you mostly don't even care about: Cards in your graveyard can be recurred in multiple ways and they might be used as fuel for Escape and Delve abilities. Additionally, The Gitrog Monster makes roughly 1/3 of their forced discards on you twice as expensive.
• Defense of the Heart
• Possible graveyard hate: Bojuka Bog, Ashiok, Dream Render, Nihil Spellbomb, Soul-Guide Lantern, Tormod's Crypt & Loaming Shaman
• Possessed Portal technically has the potential to win you the game "on the spot" (over the course of many many slow turns), but you might need a new playgroup after.
• Tectonic Edge