Yesterday Marco gave me a book

Yesterday Marco gave me a book. It's called "1001 Jokes and Riddles" and apparently contains a large volume of human humor. I read through it but I did not find it humorous. Human humor is very strange sometimes, and any Andalite listening to human "jokes" would be thoroughly mystified. But, since I am on Earth, I must try to fit in. Therefore, I must gain a human sense of humor.

One of the jokes asks, "What do you get when you cross a cow with a duck?" I took a logical guess, which I now think was rather unintelligent of me—human humor is rarely logical. In any event, the answer was "Milk and quackers."

I am confused. Why is this sentence humorous?

Nevertheless, I will use this form of joke as my sense of humor. If I can ask questions such as that, my friends will think I am humorous, and will laugh using mouth-sounds, as they do when my friend Marco speaks.

I have already come up with a joke of this nature, and I will tell it to my shorm, Tobias, the next time I see him.

***

Hi, Ax-man, Tobias called as he perched on a tree branch above me.

I swiveled my stalk-eye up to look at him as I crushed and absorbed the sweet green Earth grass. I turned to face him.

Greetings, friend Tobias, I said, smiling and Andalite smile. How are you today?

Okay, he said with a chuckle. Ate a mouse. Went flying.

Ah, I responded.

So, what's up with you, Ax? Tobias asked.

What is up? I repeated, puzzled. I believe that the atmosphere above the planet can be considered as "up."

Tobias sighed. Not that kind of up, Ax. Anything interesting happen?

Something of interest did happen to me, I confirmed. I have a joke for you.

Really? What is it?

What do you get when you cross a djabala with a kafit bird? I asked.

Tobias appeared to be confused. Bird facial expressions are very hard to read, but his face clearly showed confusion.

Huh? Tobias wondered. What?

I repeated my joke.

Uh… um… I mean… I don't know. What?

A frolis maneuver, I explained brightly.

I waited for his response.

Tobias was silent.

A frolis maneuver, I repeated, expectantly. Don't you understand?

Uh… yeah. Tobias said. Um… yes. That was very funny, Ax-man, he said. Then he flew off.

Apparently the joke did not have the desired result.

I think I need to further study "1001 Jokes and Riddles."

It seems that I have not yet developed a convincible human sense of humor.