Pachyderm Instruments is a Sebastopol, California-based builder founded by Primus bassist Les Claypool. The shop's flagship product is the Whamola, an electric washtub-style bass featuring a hinged handle, fingerboard, single pickup, and roller channel — an unorthodox one-string instrument Claypool adopted after receiving a handmade version at a Frog Brigade show and later refined for production. The Whamola has been heard on variations of the South Park theme, the Robot Chicken theme, and Claypool's Of Fungi and Foe album.

Beyond the Whamola, Pachyderm builds boutique basses including the Sleek Bass and Wally Nut Bass. Instruments are finished with natural oils or stains rather than paint or heavy coatings, leaving the wood grain and color visible and variable between pieces. The shop positions each bass as personally tested by Claypool before it leaves the workshop.

Pachyderm has also moved into electric guitar building; Sean Lennon received the first-ever Pachyderm guitar as a gift from Claypool. The company's small-batch production model and limited drops have drawn attention within the Primus fan community and the boutique bass world.

Pachyderm Instruments has 2 products cataloged on Equipboard, including Electric Basses. Their gear is featured by 2 artists, with the strongest followings in Rock. Notable users include Les Claypool and Justin Chancellor.