Have you thought about running untappers like Kiora's Follower to max out the value of the commander and mana doublers?

Forkbeard you said the tokens would fizzle but according to judges, since its all one effect, and the tokens arent placed after the effect is over but during it, the tokens would stick around.

Bloodsucker1211 Wouldn't they be 0/0 tokens though? The +1/+1 counters are placed as a separate clause to the creation of the token.

Another card I just dug out that would be great for the combo side or just big fat hydra fun: Uncage the Menagerie

PolarBearSoup they do enter as 0/0 tokens. Before the ability resolves however, you put counters on them. Doubling season also replaces the effect if you read it. It states "if an effect". So the effect would just make twice the amount of tokens using the same rules. So both would get the counters (which would double as well)

PolarBearSoup nice find on Uncage the Menagerie. It is in my Zaxara deck as well. To be honest, for this deck I feel it is a more effective tutor than Chord of Calling, allowing you to tutor creatures with X in the CMC. Chord is good for everything else but would be ineffective for X CMCs due to placing them directly into play.

Paeldroth, that was my feeling on Chord of Calling too. The downside of Uncage the Menagerie is how specific you need to be on the casting cost, as it will get you up to 2x 2cmc's, 3x 3cmc's etc. I think here the most likely use is either to get Seedborn Muse or Bloom Tender and another hydra.

Hadana's Climb  ^Flip - Enchantment that will flip into a land almost immediately in most cases. Then it's another way to give your dudes a big boost plus evasion...

Selvala, Heart of the Wilds - Card draw plus crazy mana? Seems legit here.

The more I look at the deck, the more I feel this has a huge sliding scale. One one end there is hydra tribal and X-spells without too much silly stuff. The other end is infinite mana combos and some brutal finishers. I think finding the right point on that scale will be an important factor when building the deck for your own meta.

Bloodsucker1211, That pretty much makes Doubling Season and Primal Vigor auto includes! Not sure about Parallell lives as an auto, might actually need some play data.

I found my favorite thing to do is counter a spell, unless an opponent pays 200 mana. Then using Jarad, Golgari Lich Lord to sac and kill everyone. Just a thought...

Lots of comments to catch up on here, good discussion.

EldraziPlayer54: Love the signets + talismans, but I ended up swapping out all of them in favour of a couple of clutch dorks. I'm currently running a mix of 10 ramp sources between spells, rocks, dorks & Zaxara itself. I also have Mana Reflection & Nyxbloom Ancient in the mix so I'm feeling ok about the ramp suite in general for now. I may revisit and tweak as I play the deck more based on what it needs, see if I can afford to go down a land or two as you suggested.

Paeldroth: Stonecoil Serpent is appealing and I agree with all your points, I'm just not sure if I want an honorary snake at the hydra party. Elitist, I know.

Rogue_Toaster: I did look at Kiora's Follower, but I'm undecided if it's a worthy inclusion. I just don't know what I would sacrifice to make room for it.

Bloodsucker1211: Interesting! I looked up Doubling Season on Gatherer and the ruling is this: 'The tokens and counters that Doubling Season creates are exact copies of the kind of tokens and counters that were being created in the first place.' That said, the phrasing on Zaxara is confusing due to the 0/0 piece - are you able to provide a source to that judge ruling? I just know it'll come up in games and I want to be ironclad certain. Side note, had a laugh at Jarad, Golgari Lich Lord joining the hydra fiesta - I run him in my Mimeoplasm deck, pairs great in there alongside Lord of Extinction.

PolarBearSoup: Uncage the Menagerie is an interesting tutor option, I may have to give it a go. I had Hadana's Climb  ^Flip in the original build and I ended up swapping it out early on to make way for something. I do like it though - as you say it'll flip right away and that ability is pretty great, not to mention the colour fixing land. And yeah, Selvala, Heart of the Wilds could be bonkers and should probably get in here.

Forkbeard It would create those tokens but using the same effect. Its not copying the tokens, its copying the effect. Making it trigger twice really. Does that make sense? So when Zaxara's effect happens doubling season sees it and says instead of making one 0/0 token that gets x counters on it make 2 0/0 tokens and they both get X counters on them

That makes sense when you look at it as replacing the entire effect. I'd be interesting in a proper breakdown... might go hit a rules forum for some comp rule references.

I would like to let you know that Zagoth Triome is now a thing.

Parcelbeast is a Coiling Oracle or Risen Reef on an activated ability.

Brokkos, Apex of Forever may also work but not so sure on this one. The reason I am mentioning these two creatures is because they have mutate and can function decently well on their own in the deck. Mutate works well with hydras and hydra like creatures because of their +1/+1 counters. Essentially, you can give your hydra tokens an increased base power/toughness and some other keywords or activated abilities. There's also the option of making Zaxara, the Exemplary more resilient with bigger stats.

Would also like to mention Deadly Rollick and Fierce Guardianship. Free spells with useful effects? Great!

Lastly, have you though about having Thrasios, Triton Hero as an infinite mana outlet if you don't have cards like Stroke of Genius or Exsanguinate already in hand?

I dislike that Zagoth Triome enters tapped, but I think the fetch factor + cycling make it worth it and I will certainly try it out. Likewise for the C20 'free' cycle - really like the look of those and am planning on adding a few of them around my other decks, possibly here too. As for the mutate creatures, they're neat but I think they'd be too clunky in here.

Thrasios, Triton Hero is real powerful but I'm not certain he's worth running without Laboratory Maniac and/or Thassa's Oracle. I like the current play style & deck state so I don't want to dedicate 2-3 more slots for that package just yet. Perhaps down the line if I feel like it needs more combo fuel.

There is of course one card hasn't been mentioned, but is truly amazing here... Mana Drain. Though the usual caveats apply... i.e Mana Drain is amazing in almost any deck, it is so expensive.

Absolutely PolarBearSoup, that would be amazing in this deck. I've been playing this damn game for actual decades and I still haven't managed to get my hands on a single Mana Drain (it is in my trade binder 'want list', hint hint traders out there). I should've made the extravagant purchase while Iconic Masters was still fresh and the price was down a bit.

I personally dont think harden scales worth the slot for just adding 1 extra counter and maybe god of the hunt for trample and deep glowskate to double counters

noiseFM, The deck already includes Hardened Scales.

For card reference: Nylea, God of the Hunt, Deepglow Skate.

I said I dont think harden scales is worth being in the deck

noiseFM, I think you're right. My rationale was that it was a decent value + on theme 1-drop, but Deepglow Skate is a potential finisher, good call. Static trample from Nylea would be pretty handy too, will think on that inclusion as well.

If you're going to include trample, if you have room, it's also a good idea to include deathtouch, such as from Ohran Frostfang so that you deal more damage to players. Ohran Frostfang also has the pro of drawing you more cards in the process.

Ohran Frostfang is definitely a cool card but I also don't want to stray too far off theme, y'know?

Curious if you thought about adding Chalice of the Void or Helm of the Host. The chalice has a down side of affecting you, but with the majority of x costing cards you can go around it. The helm on the commander would be a plus with more mana available and more tokens created.

Both really great cards Mudbutt, I'm just not certain they're the right fit here. CoV is particularly interesting though and the cast means it warrants consideration. Really enjoy HotH and run it in my big stompy Eldrazi deck, but I think it might be too clunky for this brew.

Zaxara Ruling: If an effect, such as that of Doubling Season, causes Zaxara's ability to create multiple Hydra tokens, they each receive X +1/+1 counters.

so the token hydra's from doubling season get the X counters as well :)

Thank you Millenhero - I finally looked it up on the Ikoria release notes and confirmed as well. I'm going to make an update here to reflect those official rulings.

Does the hydra come out after or before u cast black sun zenith