(adsbygoogle = window.adsbygoogle || []).push({}); Yeah so basically you know the way monkey steal the drops? If you wait and fallow the monkey a Perk-a-Cola bottle will appear when the monkey is changing the drop! It only lasts for a split second so you have to be like right over the monkey to get it... video below.

Do you mean the powerup has to naturally drop as a max ammo in order for the perk powerup to drop?
Cause I've seen it switch many times from insta-kill to the perk vodka bottle, then to 2x.

I saw a video from I think NGT or Syndicate or whoever (some respectful guy in zombies) who said it comes after max ammo and had video proof. I don't think it matters what it drops as.