New Neutral Minion - Yogg-Saron, Unleashed

Not gonna lie, if your deck plays more than 10 spells consistent around turn 7 you'll likely just put this in your deck as a sort of psuedo Prison of Yogg-Saron that's infinitely easier to play and likely more consistent.

There is no real downside aside from consistency. You'll likely be seeing yogg in both competitive and meme because if theres one thing hearthstone has taught us is that randomness can sometimes just win you games, albeit aggravatingly undeserved. If prison of yogg can see play Ive no reason to assume this wouldn't.

There is a small chance that you can even base an entire deck just spamming tentacles and then yogg just grants you a whole hand of 1 mana random 10 mana spells. If this gets anyway consistent we might actually see a nerf, though it'll be funny if the tentacle gets nerfed because 1/3 of the entire set would then be refundable.

So you probably want to play Yogg in a deck that runs a bunch of spells.. Or has ways to discover a bunch of spells. As for classes that could easely run yogg: Priest, Mage, Triple Blood DK, Shaman, Druid and DH come to mind. These classes could run Yogg without too much trouble. Altough non-mech Rogue might also be able to run Yogg as well. (Maybe Miracle rogue because they could use a cheap mind control or "board clear"?)

Lets look at the options:

Induce Insanity: Good one-sided board clear, can win you the game.

Reign of Chaos: Mind Control. We know that getting this effect for less than 10 mana is pretty strong thanks to Sylvanas, the Accused. This certainly can also win you the game.

Tentacle Swarm: An interesting option. This seems like a good option if you need to generate a wincondition, or if your in a control vs control matchup and want to generate some value. Of course the problem with this option is hand size, because you might not have a lot of space in hand for the tendrils.

Overall, i do see Yogg getting played a bunch in good decks and meme decks. There simply are a lot of classes that can make use of Yogg. Though with Yoggs thematic statline, don't expect to get more than 1 effect off UNLESS you can copy Yogg with cards like [Hearthstone Card (Reverbarations) Not Found].