Hecklewaggle

Reached legend with this in July 2019. It's very versatile, lots of ways to combo. Jepetto, Thaurisan, Innervate and Naturalize open up all sorts of unusual combinations of the deckswap/handcopy. This makes you resilient against most control decks running combobreakers.

Great against cyclone mage, very hard for them to burn through your armor without a timewarp/vargoth turn.

Decent against all popular agro decks like odd paladin, odd rogue, even shaman.

Tricky against Mecha'thun Warlock and Snipsnap Combos. You need to build armor and use spreading plague preemtively.

Poison seeds is great against Big Priest, but beware having them shuffled into your own deck with Psychic Scream. 

Terrible against Jade Druid.