Panda Joke

Okay, so my professor told this joke yesterday in class and it totally went over my head. I had to have my friend explain it to me before I got it, so I want to see if anyone else gets it right away. This proves that science is NOT my best subject :

A college student and a professor go out to lunch at a local restaurant. They are both enjoying their meal and the atmosphere is light and cheery. Everything is fine, when all of a sudden, a panda bear walks in. Nobody seems to really pay much attention to the panda and don't really seem to care that there is now a panda in their midst. Everyone execpt the college student.
"Do you see that?!" the college student asks his professor.
"Yeah," the professor replies.
"Well...there's a freakin panda over there and you're cool with it?"
"It's a panda."
The college student is perplexed by his professor's casualness to the whole situation, but tries not to make a big deal out of it since no one else is.
Well as the meal goes on, everything seems normal and the college student has seemed to calm down. The panda orders his food and is pretty much minding his own business. Then the waiter comes to the panda's table with the bill. That is when all hell breaks loose. The panda pulls out a gun and shoots and kills the waiter in cold blood, but still, no one seems to pay much attention to it. Now the college student is practically freaking out at this point.
"Di-did-did you see that!" he cries out to his professor again.
"Yeeeaaah," his professor replies in a 'duh' tone.
"What do you mean 'yeeaah'?! That panda just freakin killed that dude!"
"So? He's a panda. That's what pandas do."
"WHAT?! I've never seen a panda pull out a gun and just off somebody!" The professor sighs.
"Don't you take biology?"
"Yes," the student replies very confused.
"Then you should know that that behavior is really normal."
"WHAT?!"
"Go home and read your textbook. It should have it in there."

So the college student goes home and takes his professor's advice. He reads his biology book and sure enough, what happened at the restaurant is explained in the book. A South Asian mammal who eats, shoots and leaves.

(Ba dump dump, lol)

End