What's the aura for Cookie Clicker's Krumblor the cookie dragon?

In early game, I think before you get the Radiant Appetite, the best aura for idling is Elder Battalion, not the Breath of Milk. Elder Battalion gives way more CPS when you don't have all kitten upgrades. I don't know the point when milk becomes more powerful than battalion though.. I assume after purchasing the Kitten managers.. (900 quintillion)

In mid-game I recommend to play little more actively. Because when you get Dragonflight, you can then start "hunting" the Frenzy AND Dragoflight combination. This can give enormous boost even if you're clicking manually. (Using macro or automatic clicker could give INSANE amount of cookies). If idling, you should use Breath of Milk.

In late game when you have all auras, all kitten upgrades (and possibly second slot for aura). Try to get that Frenzy+Dragonflight combination when playing actively and Radiant Appetite for the second aura. If idling, use Radiant Appetite and Breath of Milk and let wrinklers come.

I use breath of milk since I just started playing like a few days ago and it helps quite a bit as the more milk you have the more cps you have. But it's just my opinion for early game.