Mr. Ping mentioned that when Po was little, he ate his imported bamboo furniture.
Not to mention "I took you inside, fed you, gave you a bath, and fed you again...and again, and tried to put some pants on you. And then I made a decision that would change my life forever. To make my soup without radishes, and to raise you as my own son. Xiao Po, my little panda."
The painting of Ping giving baby Po a piggyback ride. It goes about as well as you'd expect.
This small line from Po just before kicking wolf ass.
Po: My fist hungers for justice! (stomach rumbles) …that was my… fist.
The blind musician who calmly plays amidst all the chaos in the first fight scene, and only reacts to a sour note on the instrument Po grabbed at random to block a sword.
What's funnier is that when Po lets go, Tigress is stunned stiff.
If you keep watching, even after she instinctively dodges the Five pouncing on Po and up to the point that Shifu starts congratulating him, she still has that paralyzed, stunned look.
When Po pulls a Big Damn Heroes moment to rescue the Five before the climax, he challenges Shen from the top of a rooftop to the waterway below. But given the height, neither Shen nor his men can understand what Po's saying.
Po: (challenges are heard in mumbles at the bottom) Shen: WHAT?!
Po: Look, I don't know who you are, but please stand aside sir.
Viper: That's a lady.
Po: Oh!... Sorry! The beard threw me, it's kind of misleading. False advertising...
When Po and Tigress have the heart-to-heart/training session on the boat.
Po: I just found out that my dad isn't really my dad.
Tigress: ...your dad?
Tigress: The goose.
Po: (nods again)
Tigress:(no change of tone or expression whatsoever) ...That must have been quite a shock.
Lord Shen is practicing the speech he'll give to a defeated Po. Then a huge shadow appears on the staircase, accompanied by growls and panting. Shen nervously reaches for one of his knives and...it turns out to be one of his gorilla Mooks carrying Po, exhausted from the dozens of stairs leading up to Shen's throne room.
Shen: Greetings, Panda, we meet at—
Po: (interrupting, barely glancing at him) Hey, how ya doin'?
Then the poor kid sees the dragon grab a sheep lady to ask it a question and proceeds to freak right out.
The Toilet Humor gets kind of ridiculous, really. At one point, they take out mooks by beating up ones in front of them and throwing them out of the back of the dragon costume - which looks very much like they're nailing mooks by pooping at them at high velocity.
When Po and the Five then proceed to beat up Shen's wolf minions (long story short) Pac-Manstyle! Heck, the entire chase through Gongmen can count as this, like the rickshaw chase between Po and the Wolf Boss.
"Inner peace." (raindrop) "Pea..." (raindrop) "Inner peace." (raindrop)"AAARRRRRARGRRAUGRRHHHHH!!"(more raindrops, beat) "RRRRRARGRRAUGRRHHHHH!!" (Po starts beating his head on the mast) "Inner peace! Inner peace! Innerpeaceinnerpeaceinnerpeaceinnerpeaceinnerpeacerrarrugrarrhghh!"
Shifu reflects on Oogway selecting Po back in the previous movie, and not even trying to sugarcoat it even when Po is right there.
Shifu: Some find inner peace by meditating for fifty years. Others, like myself, find it through great pain and suffering. Po, the day you were chosen as dragon warrior... was the worst day of my life. By far. Nothing else came close. It was the worst, most painful, mind destroying horrible moment-
Shifu: -I have ever experienced *shudders*
"Why... (bonk) are there... (bonk) so...(bonk)...many...(bonk)...signs?"
Wolf Boss's preoccupation with Po's fuzzy and plushy build is just hilarious.
Wolf Boss: It fought like a demon! Big and furry, soft and squishy, kinda plush and cuddly.
Monkey saying he'll warn the group of any approaching threats with a "Caw-CAW, Caw-KEE!" like Crane's. Crane momentarily gets a bit huffy ("Excuse me, when have I ever made that noise?"), but the payoff comes when Monkey is too distracted and lets the enemy get too close.
Monkey:(Weakly) Eh-heh... caw-caw?
Immediately followed by this:
Po: You! You're mine!
Wolf Boss: I'll tell you what's gonna be yours: my fist in your plush, cuddly, super-soft face! (Monkey and Crane drop in and take down the other two wolves) Uh oh. (runs away)
The funny exchange between Po and Shen when they first meet. (DVD Commentary states that this scene is the only scene that was done with two people in the recording room. Jack Black and Gary Oldman ladies and gents!)
Shen: The only reason you are still alive is that I find your stupidity mildly amusing.
Po: Well, thank you, but I find your evilness extremely annoying!