Quickly slapped together a deck around the freshly spoiled Zaxara, the Exemplary. The main name of the game is to take advantage of Zaxara's token engine ability via  mana cost hydras + spells (current number of  mana cost cards in this brew = 28). Toss in a heap of Sultai cruelty into the mix and we've got ourselves a formidable kitchen table threat.

On top of the hefty hydra tribal flavour, there's a few other tricks in here to steer you to victory. You'll want as much mana as possible to funnel into all of those  spells and there's a couple of cards that generate infinite mana when paired with Zaxara's mana tap ability (likewise with Bloom Tender and/or Selvala, Heart of the Wilds if the conditions are met): Freed from the Real & Pemmin's Aura. If you're able to pull that combo off, here's a few of the non-hydra beat-down ways to win:

Infinite direct damage via Exsanguinate, Profane Command, Torment of Hailfire or Walking Ballista
Mill an opponent out with Blue Sun's Zenith, Braingeyser, Damnable Pact, Stroke of Genius or Villainous Wealth

On top of those instant kill combos, if you've got infinite mana to play with you'll have the means to throw down an  mana cost hydra with infinite power/toughness. Ideally you'll have Akroma's Memorial on the table for the haste/trample/evasion kill, but we've also got Icy Blast, Open Into Wonder & Rogue's Passage just in case you need to clear the path for those giant hasty hydras.

As a final alternative win condition we've got Simic Ascendancy which will stack up to 20 counters in no time. Doubling Season might have a little role to play in all of this too.

And there you have it. BUG is evil at the best of times, but I like the mix of big janky tribal tokens fun that Zaxara also lends itself to. Always welcome feedbac

First of all, I want to say thanks to everyone that has offered suggestions, ideas and critiques - it's really helped hone the deck and I've enjoyed the process. There's been a whole bunch of discussion here, nearly 50 comments in 1 week in fact! I'm going to reset the comments today to start anew, but you can always review the comments in the archive to see how the deck evolved over the course of week 1.

Second, the Ikoria release notes cleared up the token doubling debate. Here's the points on Zaxara for reference, straight from WotC:

The value of  in Zaxara's last ability is the value of  of the spell you cast.
If the spell you cast has  in its mana cost, the token gets only  counters, not twice .
The Hydra token enters the battlefield as a 0/0 creature. Any abilities that modify or trigger on this event apply. After the token is on the battlefield but before any player can take actions, +1/+1 counters are put onto the token.
If  is 0, the 0/0 Hydra token will die immediately after the ability's done resolving unless something else is raising its toughness.
If an effect, such as that of Doubling Season, causes Zaxara's ability to create multiple Hydra tokens, they each receive  +1/+1 counters.

There. Clarified. Cards like Parallel Lives & Primal Vigor suddenly appeal and I'll need to think on whether or not they need a home in here.