I just got a Ghost Pop in my loot at Slub Gut's Sanctum. I thought all of the Halloween stuff was shuffled out of rotation along with the Halloween Store? I mean, I'm not complaining - I've got nothing against Ghost Pops. But it seemed likely that they're not supposed to be showing up in loot at the moment.
Yeah, known oversight: http://forums.cardhunter.com/threads/release-3-90-18-nov-2015.8435/#post-106742 Farm those Halloween candies while you can.
