Here is my Mimeoplasm EDH deck. I run it as a graveyard combo that once it starts its pretty unstoppable. I've run through several "drafts" of this deck and have found this to be the most consistent build for the deck.
Reasons you might like to play this deck:
-you love combo-ing out in a variety of ways (but are fairly similar)
-you love having protected combos and ways to save your combo pieces in case of emergency.
-you like doing some degenerate things (i.e. turn 2 Jin-Gitaxias)
-you like playing with your graveyard
-your general can be used to recur your own creatures or exile creatures from an opponents graveyard.
Reasons you may not like this deck:
-you don't like the above reasons
-you don't like being a target without doing anything
So the deck revolves around dumping your combo pieces into the graveyard and bringing them out for a quick victory. Or if not, you can do degenerate things to slow down the game until you are able to successfully combo off and win.
The combos
The easiest combo in the deck is to Hermit Druid and flop your deck into your graveyard (since you run no basic lands), which will put Narcomoeba straight onto the battlefield and if you play a land then Bloodghast will pop out onto the battlefield as well. Now you have 3 creatures on board which you can use to flashback Dread Return your Laboratory Maniac to the field, then flashback think twice to win. This combo has a decent level of protection as you can flashback Memory's Journey to put 3 cards back into your library so you don't lose, you are just on a timer to attempt another combo.
Should the first combo fall through, luckily you have a back, you can use your general The Mimeoplasm to bring back your Necrotic Ooze to abuse the activated abilities of creatures in your graveyard. The main is tapping The Mimeoplasm / Necrotic Ooze for Bloom Tender's mana ability, then untapping him by putting a -1/-1 counter on it using Devoted Druid. Activate haste from the Thornling in your graveyard. Thornling can also provide indestructibiliy. Then remove the counter with Quillspike's ability and giving him +3/+3. Do this repeatedly to make ooze an infinite/infinite, so swing for game. If someone tries to stop the combo by destroying the ooze or exiling you can activate Sylvan Safekeeper's ability to sacrifice a land to give him shroud. The rest of the combo will still work as none of it targets. Also Bloom Tender and this combo should provide infinite mana as well.
Using this mana and the ooze if you want you can activate Oona, Queen of the Fae's ability to mill your opponents to death. Otherwise you can create infinite colorless mana by playing Tidespout Tyrant then Sol Ring tapping the Sol Ring, playing Memnite to bounce Sol Ring and create a loop to mill with Oona. If you use Body Double to copy then recur Tidespout Tyrant you can bounce everyone else's permanents to swing for game or take care of threats.
Card Choices
Combos aside, other cards in the deck were chosen to help defend you against your opponents until you can safely pull off your combo.
Wonder gives evasion. Sheoldred, Whispering Onegood recursion and hate on enemies' boards. True-Name Nemesis good to get in some small beats, especially if used with The Mimeoplasm to swing for commander damage. Lord of Extinction same as True-Name Glen Elendra Archmage good on board counterspell, can be used with Necrotic Ooze to protect the combo. Mirror-Mad Phantasm alternate way to mill yourself. Phyrexian Metamorph badass clone to get people's rocks or power creatures. Scavenging Ooze protect yourself against a living death by eating someone else's graveyard. Phyrexian Delver recursion. Fatestitcher can be unearthed for to get the 3 creatures you need to flashback Dread Return, also can be used to untap a creature or rock to get utility. Terastodon offensive destruction to take care of problems on board. Can be hard cast or recurred. Eternal Witness return important cards from graveyard, creatures/spells/etc. Sylvan Library card draw and stacking deck. Sudden Spoiling really because of the split-second to stop a stack to save yourself, or to stop someone else combo-ing off. Living Death great board wipe and recursion package.
Reasons you might like to play this deck:
-you love combo-ing out in a variety of ways (but are fairly similar)
-you love having protected combos and ways to save your combo pieces in case of emergency.
-you like doing some degenerate things (i.e. turn 2 Jin-Gitaxias)
-you like playing with your graveyard
-your general can be used to recur your own creatures or exile creatures from an opponents graveyard.
Reasons you may not like this deck:
-you don't like the above reasons
-you don't like being a target without doing anything
1 The Mimeoplasm
Artifacts
1 Sensei's Divining Top
1 Sol Ring
1 Gilded Lotus
1 Lightning Greaves
Creatures
1 Oona, Queen of the Fae
1 The Mimeoplasm
1 Sheoldred, Whispering One
1 Jin-Gitaxias, Core Augur
1 Memnite
1 Phyrexian Metamorph
1 Quillspike
1 Birds of Paradise
1 Tidespout Tyrant
1 Lord of Extinction
1 Thornling
1 Terastodon
1 Bloom Tender
1 Devoted Druid
1 Glen Elendra Archmage
1 Hermit Druid
1 Eternal Witness
1 Sylvan Safekeeper
1 Laboratory Maniac
1 Prophet of Kruphix
1 Narcomoeba
1 Wonder
1 True-Name Nemesis
1 Scavenging Ooze
1 Necrotic Ooze
1 Body Double
1 Mirror-Mad Phantasm
1 Bloodghast
1 Phyrexian Delver
1 Fatestitcher
1 Sylvan Library
1 Necromancy
1 Animate Dead
1 Dance of the Dead
Instant
1 Mystical Tutor
1 Entomb
1 Vampiric Tutor
1 Counterspell
1 Think Twice
1 Memory's Journey
1 Voidslime
1 Sudden Spoiling
1 Spell Crumple
1 Beast Within
1 Cyclonic Rift
1 Force of Will
Land
1 Tranquil Thicket
1 City of Brass
1 Rupture Spire
1 Command Tower
1 High Market
1 Flooded Strand
1 Thespian's Stage
1 Opal Palace
1 Marsh Flats
1 Exotic Orchard
1 Dimir Aqueduct
1 Dreadship Reef
1 Darkslick Shores
1 Hinterland Harbor
1 Drowned Catacomb
1 Bojuka Bog
1 Cabal Coffers
1 Verdant Catacombs
1 Woodland Cemetery
1 Temple of Mystery
1 Golgari Rot Farm
1 Transguild Promenade
1 Temple of the False God
1 Underground River
1 Forbidden Orchard
1 Llanowar Wastes
1 Bloodstained Mire
1 Yavimaya Coast
1 Simic Growth Chamber
1 Breeding Pool
1 Watery Grave
1 Overgrown Tomb
1 Vault of Whispers
1 Seat of the Synod
1 Nykthos, Shrine to Nyx
1 Urborg, Tomb of Yawgmoth
1 Reanimate
1 Demonic Tutor
1 Exhume
1 Life from the Loam
1 Beseech the Queen
1 Buried Alive
1 Diabolic Tutor
1 Dread Return
1 Living Death
1 Increasing Ambition
1 Green Sun's Zenith
1 Diabolic Revelation
1 Life // Death
So the deck revolves around dumping your combo pieces into the graveyard and bringing them out for a quick victory. Or if not, you can do degenerate things to slow down the game until you are able to successfully combo off and win.
The combos
The easiest combo in the deck is to Hermit Druid and flop your deck into your graveyard (since you run no basic lands), which will put Narcomoeba straight onto the battlefield and if you play a land then Bloodghast will pop out onto the battlefield as well. Now you have 3 creatures on board which you can use to flashback Dread Return your Laboratory Maniac to the field, then flashback think twice to win. This combo has a decent level of protection as you can flashback Memory's Journey to put 3 cards back into your library so you don't lose, you are just on a timer to attempt another combo.
Should the first combo fall through, luckily you have a back, you can use your general The Mimeoplasm to bring back your Necrotic Ooze to abuse the activated abilities of creatures in your graveyard. The main is tapping The Mimeoplasm / Necrotic Ooze for Bloom Tender's mana ability, then untapping him by putting a -1/-1 counter on it using Devoted Druid. Activate haste from the Thornling in your graveyard. Thornling can also provide indestructibiliy. Then remove the counter with Quillspike's ability and giving him +3/+3. Do this repeatedly to make ooze an infinite/infinite, so swing for game. If someone tries to stop the combo by destroying the ooze or exiling you can activate Sylvan Safekeeper's ability to sacrifice a land to give him shroud. The rest of the combo will still work as none of it targets. Also Bloom Tender and this combo should provide infinite mana as well.
Using this mana and the ooze if you want you can activate Oona, Queen of the Fae's ability to mill your opponents to death. Otherwise you can create infinite colorless mana by playing Tidespout Tyrant then Sol Ring tapping the Sol Ring, playing Memnite to bounce Sol Ring and create a loop to mill with Oona. If you use Body Double to copy then recur Tidespout Tyrant you can bounce everyone else's permanents to swing for game or take care of threats.
Card Choices
Combos aside, other cards in the deck were chosen to help defend you against your opponents until you can safely pull off your combo.
Wonder gives evasion.
Sheoldred, Whispering Onegood recursion and hate on enemies' boards.
True-Name Nemesis good to get in some small beats, especially if used with The Mimeoplasm to swing for commander damage.
Lord of Extinction same as True-Name
Glen Elendra Archmage good on board counterspell, can be used with Necrotic Ooze to protect the combo.
Mirror-Mad Phantasm alternate way to mill yourself.
Phyrexian Metamorph badass clone to get people's rocks or power creatures.
Scavenging Ooze protect yourself against a living death by eating someone else's graveyard.
Phyrexian Delver recursion.
Fatestitcher can be unearthed for
Terastodon offensive destruction to take care of problems on board. Can be hard cast or recurred.
Eternal Witness return important cards from graveyard, creatures/spells/etc.
Sylvan Library card draw and stacking deck.
Sudden Spoiling really because of the split-second to stop a stack to save yourself, or to stop someone else combo-ing off.
Living Death great board wipe and recursion package.