 Kenny is turned into a zombie after a mortician accidentally knocks Worcestershire sauce , a fermented liquid condiment , into his embalming fluid . Parker and Stone originally planned to have a Dr Pepper fall into the embalming fluid ( in a belated response to that product 's slogan " Dr Pepper , What 's the Worst That Could Happen ? " ) , but it was changed after the soft drink company objected to that use of their product . 
