Here’s a link to a Electro-Harmonix’s “Effectology” page where they show you tons of ways to create all sorts of sounds samples using only a guitar and their effect pedals. Click Here to check out all the different sounds you can make.
The Big Muff Pi by Electro-Harmonix
No Synths, computers, samplers, or midi controls, just old school strings and stompboxes. http://www.ehx.com/products/big-muff-pi