What types of effects are the Wall-E and Cow Girl pedals?

I am told that they are both Harmonic Percolator-type pedals designed by Mr. Bill from Guitar Works in Evanston. The Cow Girl is the Wall-E with both knobs at full.

The white one with the knobs is one of a set of four I had made, three were a gift to the band Pussy Galore, and had little stickers on them that said PUSSY FUZZ. Nice one Mr Bill. The other one is ours. The "cowgirl" is actually Bond Girl Pussy Galore. There's also a pedal with a cat on it that is the same thing. All were made by Mr Bill.