Simic Tamiyo ARENA (Pioneer)

4 Tamiyo, Collector of Tales
3 Kiora, Behemoth Beckoner
Tamiyo's abilities lets you get through your deck and have a chance at getting the card you need most. As other important cards get milled, the second ability lets you put those into your hand at Sorcery speed and at NO MANA COST. The use of Surveil can also help support Tamiyo's second ability.
Kiora, Behemoth Beckoner just makes your Bioessence Hydra massive, especially if you pull it from your graveyard and then play it when you already have a huge hydra in play. In addition, the extra card draw happens, right about the time you are pushing to take over the battlefield, or clawing to keep yourself in the game.

4 Arboreal Grazer
3 Growth Spiral
These two cards are part of the key standard Simic land generation used in other decks, like Scapeshift. This engine is key to a quick start for this deck and puts it in a position to dominate by turn 3 or 4. Taking advantage of having Sphinx of Foresight in your hand can really help put you in an excellent starting position with a mix of 4 lands, Arboreal Grazer, and Growth Spiral, having all 4 lands in play and untapped for turn 3.

4 Sphinx of Foresight
1 Hydroid Krasis
4 Frilled Mystic
These three creatures, combined within the land engine are the guts of this deck. 4/4 Flyer, X/X card draw and life gain, and a 3/2 counterspell are the means to winning with this deck. The Sphinx of Foresight in your opening hand helps you maximize your early game. Hydroind Krasis is a huge flying body that give you both cards and life, really boosting your mid to late game. Frilled Mystic to shut down their game breakers and leave a dangerous body on the battlefield.

3 Sinister Sabotage
3 Unexplained Disappearance
Counter spells and bounce are a part of the control portion of this deck. Working win conjunction with Frilled Mystic to prevent spells, and bounce what you could not counter, it helps keep the board in your favor. The Surveil supports Tamiyo's second ability, and give you another chance to put a card in there that helps your deck shift fate in your favor.

2 Lazotep Plating
2 Kraul Harpooner
These two cards are my current flex selections. Added to the deck to help deal with White and Black flyers in current popular decks and to protect your Hydras at critical points of the game.

4 Bioessence Hydra
Ah, the big surprise beater creature, a very traditionally green play, that plays off from your Tamiyo, Collector of Tales to pressure your opponent for a fast victory. A huge body, that gets bigger as you use your planeswalker's plus ability has trample, so chump blocking does not stop you from killing their planeswalker's or just slapping them upside their head. Jamie Wakefield would be proud.