Board Thread:General Discussion/@comment-4720870-20130610214628/@comment-4971130-20131015123508

Science-wise a mutation means that your DNA-code gets altered somehow, so I suppose the Krang mutagen merges another lifeform's DNA into your own if it can find any in your body, it also seems that during this process, your DNA also gets temporarily broken, preparing to mix it with the new DNA. However, Timothy didn't have any other DNA in his body besides his own, so the mutagen broke his DNA and left it there, turning him into a mishmash of organs in some green gell-like substance. This is a cartoon however, and we shouldn't mix real life science into it.