Pearl make drums these days, but back in the early 80s, they had  a line  of effects pedals made by Japanese giants Korg. This is a fixed wah, or a resonant filter, type of idea. It's kinda similar to the Boss Enhancer, but not the same. You get a high pass filter, controlled by the frequency knob. The color control adds a boost to the frequencies around the cutoff point, while the multipeak control basically adds highs. You also get a balance control, to blend in the dry signal. It sounds like a curious option, but very few things make a solo cut through a mix like a cocked-wah, and having that on tap is very handy, and blending in the dry signal helps too. And yes: I did buy it because I thought the name was funny.

Model: Pearl TH-20 Thriller
Made: Japan, 1982 approx
Serial: 001787
Type: fixed wah/filter
Power Input: standard 9v DC centre-negative (supply not included)
Accessories: none

Condition notes: used, no major marks. Tested and fully functional.
Overall: very good condition (8/10)