That first panel isn't that a Tom and Jerry bit? I remember this scene with Jerry licking a lemon in front of Tom.
Can't seem to remember which short it was featured in

https://youtu.be/_TeqBZEHU5I 04:01

"La...Laa... Laa.... La.... Laaaaaaaa...."

Honestly one of my favourite scene. Thanks for the reference

Original song. (Largo al factotum, from The Barber of Seville).

Good times. Heard it often in a lot of the old cartoons.

Bugs Bunny ver..

The Whale Who Wanted to Sing at the Met.

Robin Williams also had a go at it in the opening scene of Mrs. Doubtfire. Animated by Chuck Jones too (same guy who did that Tom & Jerry short)!

(They actually had the whole short animated and voiced too.)

And here's a compilation of several shorts featuring Largo al factotum.

Edit: And a video excerpt from an actual operatic performance.

The day of reckoning came

My therapis: "Shredded Shangri-La doesn't exist, she can't hurt you."

Shredded Shangri-La: