Reddit, what's the worse thing you've ever tasted?

Ok, i'll start. In Elementary School, when I was at recess, my friend dared me to eat grass mixed with mulch mixed with that grounded up tire type rubber mulch (I don't know if anybody else had it, but at my school I did). Anyways, being the stupid little try-anything-once kid I was in first grade, I did it. I threw up as I was chewing it and the vomit had mixed in with the horrible concoction I had made. And I had swallowed it. It was horrible. I was sick for 3 days. So Reddit, what is the worst thing you had ever tasted, be it real food or mixed up ground material?