James Fenimore Cooper's Literary Offenses
You didn't want to get in Twain's sights when he had a grouch on.
Yep. I first read "Literary Offenses" at my dad's behest, just after I finished reading "The Last of the Mohicans" in high school.
One day in study hall, I was smiling and nodding in agreement as Twain ticked off the eighteen literary devices that Cooper had mangled. When I got to this one, I busted out laughing in a dead-quiet room. Naturally, one of the room monitors came to chastise me. I simply shrugged and pointed to this paragraph:
7. They require that when a personage talks like an illustrated, gilt-edged, tree-calf, hand-tooled, seven- dollar Friendship's Offering in the beginning of a paragraph, he shall not talk like a negro minstrel in the end of it. But this rule is flung down and danced upon in the "Deerslayer" tale.
I also love how Twain's indignation starts out hot, rises to a crescendo and then tapers away, as though he were physically spent. He really put a lot of himself into his writing style.