A Funny Joke

Rebecca (age 3 years and 6 months) told a really funny joke this week. She tells jokes a lot and we have to pretend to be tickled by them because she tries really hard and is only 3. Then she came up with this one.
Rebecca: Knock, knock.
Dan: Who's there?
Rebecca: Choolah [She takes great pleasure in making up words, using them, and then informing us of their meaning.]
Dan: Choolah who?
Rebecca: [A pause as she stumbles over some sounds and clearly doesn't have a final line prepared] Uh, well,.... Give me a water buffalo and I will let you sleep!
We looked at each other and absolutely cracked up. It was just so 'out there' that it was truly funny. She was so excited that we were treated to the same joke over and over and over. And at that point, we were back to faking it.