Play your deathrattles and taunts to resummon them with Hadronox and N'Zoth, the Corruptor.

Play more N'Zoth, the Corruptor with the help of Flobbidinous Floop and Zola the Gorgon and Elise the Enlightened

If Hadronox gets in N'Zoth, the Corruptor's pool it's pretty much gg -because if they try to clear the board with Brawl as example, a new board can come out of Hadronox.

Scarab Beetle and Slime (the 1/2 Slime taunt of Sludge Belcher not the Warrior one as shown here) are weak taunts to resummon of Hadronox indeed, but you really need good taunt cards if you want to survive against Aggro.
Spreading Plague is almost a dead card against Control anyway so you can be more greedy and influence the taunt pool a bit more.

-Note, All deathrattles resolve before the 2/2 Treants are summoned. That means you can Poison Seeds their board to 2/2 Treants (assuming they don't have certain deathrattles) but our board won't if Hadronox is up, instead we will get our taunt minions.