So we all know Mark Twain, that famous author who's books you didn't read in English class. Unfortunately, no teacher ever covered how Mark Twain was the biggest cat person mankind has ever seen. Seriously, this man owned nineteen cats at one point! Think of how much kitty litter that would be! There would be hairballs everywhere! Taking care of nineteen cats simultaneously sounds like a full-time job, so I'm amazed he was able to get anything else done! When he had to travel, Twain would even rent cats from owners during his stay, not being able to be away from any sort of cat for very long.
So if you own nineteen cats, wouldn't you run out of names for them? Not if you're Mark Twain. He chose the weirdest names he could find, including Beezlebub, Blatherskite, Buffalo Bill, Satan, Sin, Sour Mash, Zoroaster, Soapy Sal, and Pestilence. Imagine being Mark Twain's neighbor and hearing him scolding Satan for scratching the couch cushions. I would have had so many questions.
At once point his cat Bambino ran away, so Twain frantically placed an ad in as many New York newspapers as he could, looking for his precious cat. Well Bambino returned home on his own a few days later, but for the next several months, people would turn up on his front porch, claiming to be giving him the cat he had already found. I would not be surprised if Twain just took these cats in anyway and added them to his very busy household.
Would Huckleberry Finn be more enjoyable if all the human characters were cats? The lack of opposable thumbs would make things more difficult. I honestly think this would be a fantastic adaptation though.