What's a good knock knock joke to use to introduce yourself?

[Aizel]

So, I need real good knock knock jokes that I can use to introduce myself. I am doing a freshman orientation thing and I am a mentor and I will introduce myself many times. So, please help me come with a good knock knock joke that will make the freshmen remember me because of that joke. And it SHOULD BE APPROPRIATE!!! For example, I know this is corny but i want the jokes to be this way.
Me: Knock Knock
Them: Who's there?
Me: Who.
Them: Who Who?
Me: Whose there I am! Kelly McGovern, reporting for duty!