Yenna, Redtooth Regent + Chatterfang, Squirrel General + Ashnod's Altar + Thaumatog

Yenna, Redtooth Regent

Chatterfang, Squirrel General

Ashnod's Altar

Thaumatog

How it works

1. Activate Yenna by paying 2 and tapping it, creating a token copy of an Aura you control and a 1/1 Squirrel creature token, then untapping Yenna and causing you to scry 2.
2. Activate Ashnod's Altar by sacrificing the Squirrel, adding CC.
3. Activate Thaumatog's second ability by sacrificing the Aura token, giving Thaumatog +1/+1 until end of turn.
4. Repeat.

This clever engine sets up an exponential loop by leaning on Chatterfang, Squirrel General's replacement effect to turn a simple spell-copying action into raw material. When Yenna, Redtooth Regent uses its tap ability to copy an Aura you control, Chatterfang makes sure a 1/1 green Squirrel token tags along for the ride, and since that Aura token was created, Yenna untaps to do it all over again. You then feed that bonus Squirrel into Ashnod's Altar to generate the exact mana needed to pay for Yenna's activation cost, while Thaumatog steps in to consume the freshly generated Aura token for parts so the board stays clear for the next iteration. It is a wonderfully self-sustaining loop that uses every piece of the puzzle to churn through your deck with infinite scrys while pumping Thaumatog to staggering proportions!