There is a rumor out there about Billy Crystal. No, not whether he's Jewish; it should be obvious to a lamppost that he is. The rumor is about Billy Crystal's name.
You see, many Jews change their name to something a little less Jewy when they enter show business. So Allan Stewart Konigsberg becomes Woody Allen, Melvin Kaminsky becomes Mel Brooks, Lawrence Harvey Zeiger becomes Larry King, etc. So it would make sense if Billy Crystal's tidy moniker was a front for something hideous.
And the rumor says that it is: Israel William Krisstalsterne. Our tongue hurts from just saying it.
Well, the rumor turns out to be false. Billy Crystal's real name is... William Crystal. William Edward Crystal, if you want to be precise.
No, seriously, Israel William Krisstalsterne? Even us Jews would never come up with something so hideous...