The scene where the temple collapses. I saw it at the age of six and almost passed out from laughing.
As the precursor to this, when Louis suddenly finds himself being a Load-Bearing Hero (or Boss) for the temple, and is thus completely at Baloo's Tickle Torture mercy. The expression on Baloo's face when he realizes this and goes in for the kill is priceless.
And just before that, when they're all fighting over Mowgli. King Louie grabs him from Bagheera, then Baloo yanks him out of Louie's hands and bonks Louie over the head with a hilarious thumping noise. I used to rewind that bit multiple times.
"Will you stop that silly beat business and listen?"
This scene when Hathi is being convinced to help search for Mowgli:
Junior: Pop, the man cub and I are friends. He'll get hurt if we don't find him. Please, Pop, sir? Please? Hathi: Now don't you worry, son. Your father had a plan in mind all the time. Winifred:(sarcastically) Sure you did!
The whole "What we gonna do?" gag between the vultures.
"Don't start that again!"
Baloo interrupting his own moving epitaph, prompting indignant (and hilarious) fury from Bagheera.
Hathi: Wipe that smile of your face! This is the army! (the elephant frowns)
What happens when Hathi forgets to say, "Halt!" It's Stock Footage from one of Disney's cartoons, Goliath II.
Mowgli: And they say an elephant never forgets.
This exchange between Buzzy and Baloo after the vultures rescue him from Shere Khan:
Buzzy: He's safe now! You can let go, Baloo!
Baloo: Are you kiddin'? There's teeth on the other end!
When Kaa got a knot on his tail and it's stuck between two branches.
Mowgli: Bagheera, he's got a knot on his tail. Kaa: He he he, '"'he's got a knot on his tail"''.
The 1994 Disney live-action movie
Mowgli is afraid of his own reflection, so he pushes the mirror away, which hits the doctor.
At a party, Mowgli catches a fly, looks over at two girls, smiles, and then seemingly eats it. The girls walk away in disgust. When they're gone, Mowgli reveals the fly completely unharmed...he'd just pretended to eat it to gross them out.