Pedals that stack with the Animals Pedal Double Spy Mission is Imp Filter

Electro-Harmonix Big Muff Pi

The Big Muff's thick, creamy fuzz gives the Imp Filter's quacky envelope sweep somewhere heavier to land.

Walrus Audio EB-10

The EB-10's boutique preamp boost gives the Imp Filter's envelope sweep a fuller gain stage to push into.

Caroline Guitar Company Meteore

Keep Meteore's warm, lo-fi spring reverb trailing after the Imp Filter's vowelly envelope sweep, not before, or the reverb smears the filter. — goes in the amp's FX loop (or last, into a clean amp)

Dunlop - MXR Carbon Copy Deluxe Analog Delay

Run the Carbon Copy Deluxe's warm analog delay after the Imp Filter's quacky envelope sweep settles, so the repeats trail a defined tone. — goes in the amp's FX loop (or last, into a clean amp)