Grin. That silly analogy aside, mutations aren't passed on at a 100% rate for a variety of reasons even in an ideal environment. First and foremost, most observed mutations are due to changes in context, not changes in the DNA coding sequences. Add the right chemicals to frogs and you get frogs with both male and female organs, but when they breed without the presence of said chemical, you do not see 100% of their offspring with the reproductive organs of both genders, for instance. Breed a two-headed snake and you once again do not see a 100% success rate in that mutation being passed to its offspring.
Until the DNA itself is changed and copied, you don't even approach a 100% expected value for mutations to propagate.
Even when DNA is changed, there is no guarantee that the copying process will always (i.e., 100%) pass on the change. The copying process isn't that efficient, moreover, the mutation could very well harm the copying process itself presuming that we are speaking more broadly than a "neutral" mutation (an oxymoron - a more accurate term would be a non-sequencing change, such as when no-op instructions are "mutated" rather than when active code is changed).
Where did that come from?
Are you even aware that you are mixing a number of concepts in your posts? You've jumbled mutation rates, epigenetic mutations, teratogenic mutations, and transmission fidelity (which is what I was speaking to) together as if they all have the same probabilities.