Go back in time and kill Hitler as a baby. He'd be so freaked out that a baby is trying to murder him, you'll have the element of surprise.

Hitler asks a jewish kid... Hitler wants to hear the dreams of jewish kids. So, he visits Auschwitz and finds one kid sitting in a corner, freezing to death. ""Hallo kinder, what is your dream?"" ""Herr Hitler, when I grow-"" ""IF..IF you grow up.""

"Uh-oh!" - My toddler, looking me dead in the eye while he feeds his dinner to the dog

HERE'S A KID WITH NO ARMS AND NO LEGS AND HIS PARENTS ARE DEAD AND YOU'LL DIE SOON TOO, BUY THINGS. - Super Bowl Commercials in a nut shell