Hearthpwn

The basis of the deck is to constantly pull taunt minions and tigers from your deck so your opponent will have a hard time clearing your board/getting through your taunts. With a sticky board, you can reliably finish off with branching paths > +2 attack on all your minions.

This deck is effective against both control and (somewhat) aggro with a 57% 56% winrate over 102 18 games (latest version). Although it's kinda too slow in the current meta.

The jasper spellstone is a good early-game removal and synergies with the abundant armor-gain in the deck, especially Malfurion the Pestilent. It can also pop your silver vanguard and cubes when upgraded once/twice, but the cubes are often unnecessary to pop unless you're playing around a silence effect.

Naturalize can pop your hadronox and is a perfect counter to even-warlock's turn-3 giant because it kills it AND mills him 2 cards, so it's a good keep against even-warlock.

Astral tiger is an infinite source of recruits and an anti-fatigue card. A good cube target against control only.

Umbra generates a lot of value with the deathrattle cards: shuffles more copies of astral tigers in the deck and cube shenanigans. It may suck recruiting her off of oaken summons early in the game, but she's actually good when recruited off of grizzled guardian because the opponent would have probably exhausted their mana/minions killing off the guardian, especially when a taunt minion is recruited along with Umbra. You can then play your expensive deathrattle cards in the following turn like silver vanguard, another grizzled guarding, or even hadronox which would summon another grizzled guardian.

The cube can generates loads of value, and can immediately fill the board with 3/5s if played on a grizzled guardian with umbra on board, which also fits the curve (8 mana grizzled guardian, 9 mana umbra+cube).

Dollmaster Dorian superb in this deck because it has a lot of draw and most minions are good targets.

Silver vanguard can help find key minions if they are not drawn on time.

Lich King is a must-have in a taunt based deck.

Only 1 ultimate infestation because it's hard to dump your hand in this deck.

Mulligan:

-Always go for wild growth and oaken summons.

-Against aggro: spellstone and swipe (and maybe biology project).

-Against control: maybe dollmaster.

-Against evenlock: naturalize.

Edit: New version with a Juicy Psychmelon and more ramp. The melon is there for the obvious hella sick Dollmaster synergy. Also swapped silver vangaurd for dreampetal florist because it's a cube/umbra combo enabler without a 2-turn set-up and vangaurd can become a dead card if all 8-drops are drawn. She also adds to the Dollmaster+melon combo by discounting the big boys you drew. Added 2xbiology projects because the deck has 0 early game and relies on 4 mana crystals. Kinda hypocritical not having a second nourish though, but the deck is already too tight to make additions.

Possible additions: Master Oakheart, Faceless Manipulator, Witching Hour (requires removing Malfurion the Pestilent).

The deck at its prime:

Demonstrating the stickiness of the board: