Pedals that stack with the Fender Hello Kitty Fuzz

Walrus Audio Julianna Deluxe Chorus/Vibrato

Run Walrus Audio Julianna Deluxe Chorus/Vibrato after Fender Hello Kitty Fuzz in the signal chain, clear of Fender Hello Kitty Fuzz's own gain stage

Aguilar Octamizer (Bass Octaver)

Aguilar Octamizer (Bass Octaver) stacks octave on top of the fuzzy already here

Fender Blender

Fender Blender layers octave onto an already fuzzy signal

Walrus Audio Melee Wall of Noise Black

Put Walrus Audio Melee Wall of Noise Black after Fender Hello Kitty Fuzz in the signal chain, clear of Fender Hello Kitty Fuzz's own gain stage — goes in the amp's FX loop (or last, into a clean amp)

Electro-Harmonix Stereo Memory Man Vintage

Electro-Harmonix Stereo Memory Man Vintage's analog warmth voice goes after Fender Hello Kitty Fuzz in the signal chain — it's not there to compete with Fender Hello Kitty Fuzz's own fuzzy character — goes in the amp's FX loop (or last, into a clean amp)

Aphex Punch Factory Compressor

Aphex Punch Factory Compressor's own transparent character is the real reason this is worth trying