@vault: Sure.

You activate Hermit Druid or trigger Cephalid Illusionist, milling your library. Narcomoeba is returned to the battlefield, and you pay to unearth Fatestitcher. From there, you sacrifice all three to flash back Dread Return targeting Necrotic Ooze.

Necrotic Ooze has the activated abilities of Kiki-Jiki, Mirror Breaker and Mogg Fanatic. Anger is in the graveyard, so you can tap Necrotic Ooze to copy itself and then tap the copy to copy itself. You proceed and recopy Necrotic Oozes until you have an arbitrarily large number of them. Then, you sacrifice the tokens to activate the ability they inherit from Mogg Fanatic and kill your opponents.

@KillthatBUG: Yes it does. I must have confused the wording with that of Eladamri's Call when I typed my response.

I suppose, then, that there's no reason not to make the switch. I may drop Ethereal Champion and run both.

Also, @vault: Bitter Ordeal isn't an instant win, and it requires that I actually have Bitter Ordeal in hand. One of the strengths of this deck is that you don't need any combo components in hand in order to win; they're all yard-based loops.

Caller of the Claw is used as a secondary win condition in case an opponent gets rid of Necrotic Ooze somehow (maybe with Praetor's Grasp or something).

@SimicPower: I haven't built this deck IRL, and I don't know if I will. I have the resources to build it, but I don't really play anymore, so it's probably not worthwhile to actually put everything together.

This deck is pretty disgusting, and takes a different turn on the standard Hermit Druid combo. You'll get a +1 from me.

Anyways, I have some suggestions, not sure if they are ideal or not though.

Lim-Dul's Vault is a good way to tutor and set up your draws. It can hurt a bit, but it's like that you are playing against all infinite combo decks, so life isn't super relevant.

Sylvan Safekeeper can protect your combo. Necrotic Ooze can also use this ability if needed.

Mother of Runes can protect your combo. Necrotic Ooze can also use this ability if needed.

Orim's Chant can slow down your opponents and force out counterspells. Not quite as good in multiplayer, but still one to consider.

Regrowth lets you reset if a key card is countered. Always helpful.

Imperial Recruiter lets you find Hermit Druid or Cephalid Illusionist. Might be a little too slow.

As for cards to cut:

Leyline of Anticipation seems pretty weak. Unless it's in your opening hand, it's a dead card. I would cut it.

Ethereal Champion seems unnecessary. I wouldn't bother running it.

I've seen (and played against) an alternate win-con version of this. Its annoyingly fast. Have you considered the following?

Morselhoarder + Spikeshot Elder

Morselhoarder + Devoted Druid means that Necrotic Ooze can tap for green. Then you put DD's ability on the stack to untap. You get he -1/-1 counter (as part of the cost). Not you have a counter for Morselhoarder's ability to eat (which is a mana ability) menaing you never have to pass priority. Infinite mana means you can then dump it all into Spikeshot Elder's ability a bunch of times, never passing priority until you have like a billion instances of the ability on the stack. And you haven't passed priority once.

Also, I feel like Survival of the Fittest would be at home here. With enough green, you can dig for the combo pieces in one turn.

@lemmingllama & enpc: Lots of good suggestions. Thanks!

I considered Lim-Dul's Vault because I also run it in my BUG deck, but I didn't put it into this deck at first. I may slide it in over one of the less efficient tutors.

Sylvan Safekeeper isn't the best option. I can protect Hermit Druid with it, but shroud disrupts Cephalid Illusionist and Necrotic Ooze.

Mother of Runes could be viable, but I think I would have to test the deck to know for sure.

I don't really prefer proactive cards like Orim's Chant. They're a little riskier than counterspells, and I can only really affect one player with them.

Regrowth is an option. If I determine in testing that some of these cards are unnecessary, I'll be sure to consider adding it.

Imperial Recruiter is, as you said, a bit slow.

I agree with both cut suggestions.

The Morselhoarder + Spikeshot Elder combo is lewd. Added.

Survival of the Fittest added to maybeboard (pending deck space).

Epochalyptik: the +1 finally worked and can you explain the Morselhoarder + Spikeshot Elder combo?

I would probably recommend Noxious Revival over regrowth. Instant speed where you can pay phyrexian mana is awesome, not to mention you can buy yourself another turn if milled out and you have the ability to target other player's stuff to shutdown graveyard based decks/tuck away a creature in an opponent's graveyard so you can safely Crypt Champion. I run it in my Saffi Eriksdotter deck and have been really impressed with it.

@klone13: It's in the primer.

@enpc: I'll add it to the maybeboard.

One more thing (sorry about the stream of posts), have you considered Dryad Arbor? You can get it with fetches and its a creature you can sac to Dread Return/Diabolic Intent.

That's a fair point. I hadn't thought about using it for Dread Return and Diabolic Intent. I might drop a shock for that.

Also, post as many ideas as you have. I'll take a notification and a better deck over neither any day.

No problem then, if I have another brainwave I'll let you know. I have been considering building a hermit druid Damia deck for about 6 months now, you've inspired me to actually get a list together. But I think I wanna use Prossh as the general though. No blue makes it a challenge :P

No blue? I don't understand why you would do that. That's like saying you don't want free candy.

Explore for land and draw?

Explore is kind of expensive when you consider what it really does for the deck. The extra land would be more valuable if it weren't stapled to a CMC-2 spell, so that land doesn't really ramp on the turn it needs to. The cantrip is the more important part, and there are CMC-1 spells that do that.

Normally, the deck likes to go
T1: Land, maybe a ramp card, maybe a tutor
T2: Land, Hermit Druid or Lightning Greaves or a tutor
T3: Land, combo or Hermit Druid or Lightning Greaves
T4: Definite combo if not in T3 unless something's wrong

So 2-drop ramp and non-tutor spells are in an awkward place on the curve. They're just too expensive to see opening play, and they have to compete with more valuable cards in the second turn.

It may not be the absolute best option available, but what about something like Silence to protect your combo the turn you go off? Yes, it may be proactive (And also risky versus instant speed removal), but it affects all opponents, forcing them to either have an answer or lose.

Something like Chord of Calling might also be interesting, as it's an instant-speed way to tutor up a Hermit Druid- Which can very easily catch your opponents off-guard.

I don't like Silence because an opponent can respond to it with a removal spell, in which case I'd have to invest more to counteract the removal than I would have had to if I had just held a counterspell in the first place. Say I cast Silence, and an opponent casts Doom Blade in response. I'd still need to have the mana to activate Hermit Druid's ability, possibly to unearth Fatestitcher, and to counter the removal spell (because I can't cast Dread Return until the stack is empty). It's not advantageous to bait spells if one of those spells could actually stop me because I invested in the bait.

Chord of Calling is too expensive, in my opinion. It needs to be cast for to find Hermit Druid. I probably wouldn't be able to convoke that down to the point where it would be more viable than just tutoring for Hermit Druid, and I also probably wouldn't be able to back it up with countermagic because of the cost.

Doesn't Unburial Rites seem a bit slow if you are trying to combo off by turn 3 or 4?

Also, what would you tutor for with Personal Tutor and Mystical Tutor?

Just a small typo: in the primer under "Why Cromat?" it still says "Why Reaper King?".

This makes me think that Hermit Druid might be banned in commander soon. I don't think the RC is so kind about consistent turn 3/4 wins.

@dragon_slayer: A fair point. I put it in more because of the flashback, but I realize now that I don't really have an opportunity to use it as a failsafe because it's a sorcery. I would need to main Memory's Journey and have enough mana to flash back both to prevent a loss on draw step.

Personal Tutor and Mystical Tutor find other tutors or, if I already have the combo creature in hand, a counterspell.

@SimicPower: I would hope not. I would estimate that Hermit Druid makes up a very small percentage of the meta (it usually only sees play in hypercompetitive decks, and those are the ones being run in side events). Further, this definitely isn't the only T3/T4 deck in the format, (although it is fairly consistent because you don't have to be as apprehensive about plays with this deck as you do with some others).

I know that the RC is largely casual, but I hope that they're liberal enough to allow decks like this to persist in other playgroups.

Really, the only thing that binds me to the RC is the fact that they set the standard that players use in events and in new playgroups. Many playgroups already pass house rules, and I think that's part of the reason the RC generally doesn't ban a whole lot of cards (the ban list isn't that heavyhanded when all is considered).

Have you considered Laboratory Maniac and something like Deep Analysis as an alternate win-con?

@SimicPower: It's certainly an interesting thought, but I would need a reliable way to reanimate Laboratory Maniac. The issue I foresee is that this deck commits enough resources to the main combos that it doesn't really have the ability to also reanimate or cast Laboratory Maniac and flash back Deep Analysis. I would need to play Laboratory Maniac, set off the mill ability (or abilities), and then flash back Deep Analysis.

Update:
Dropped Unburial Rites
Added Bloodghast

Bloodghast provides extra security for the Dread Return cost.

That combo uses Laboratory Maniac + Azami, Lady of Scrolls + Angel of Glory's Rise. You deck mill, Dread Return the angel which in turn brings back Azami and Lab Maniac. You can then use Azami's ability, tapping her/Maniac to draw yourself out with a draw redundancy of the other untapped wizard.

Did I mention there are a few Hermit Druid combos :P

I thought this shell was busted. But I was not prepared for how busted it truly is.

But seriously, it's viable, but I don't know if I should include it. I already have the Crypt Champion + Saffi Eriksdotter + Caller of the Claw backup combo, and I'm basically just swapping alternate win conditions around.

Interestingly, I can execute a partial mill with Cephalid Illusionist and still win with the Crypt Champion combo, but I could not do the same with the Laboratory Maniac combo. But the Laboratory Maniac combo can win even if I have no way to interact with opponents maybe there's a Crawlspace out to preempt infinite token combat victories and all my other options are shot.

I feel like this is just microanalysis. In all actuality, and if I built the deck, I'd probably run the Laboratory Maniac combo because it looks better in foil.