You get Perkeo from a Spectral Pack in the shop during Ante 3 after defeating the small blind. I was able to find Trading Card, Mime, and Baron later in the run as well.

Steps: Skip first two blinds, defeat boss blind with four of a kind kings. Open both Buffoon Packs to get Lusty Joker and Trading Card (I sold Lusty to Polychrome Trading Card.) Free reroll in the shop gives Foil Stuntman. I took the investment tag and skipped the first blind of Ante 2 as well. This gets you up to the point where you can get Perkeo. I rerolled in most shops until I found a Cryptid, and copied as many steel kings as I could. Worked out super well when Mime and Baron showed up around the same time after going into endless.