In 1937, Walter Rollin Brooks, a journeyman writer from upstate New York, sold a story called “The Talking Horse” to the magazine Liberty. The conceit was silly but certainly not for kids: a champagne-swilling adman named Wilbur Pope, living in Westchester with his profligate socialite wife, Carlotta, bonds with his drinking buddy Ed, who just so happens to be a horse living in his barn. Ed, for some unexplained reason, can talk, and he has a dirty mouth. He recounts lascivious stories, guzzles booze, and gossips with Wilbur about Carlotta’s flagrant social climbing. Brooks went on to publish dozens of “Mr. Ed” stories in adult magazines, and though he eventually became a writer of children’s books his talking-horse stories remained decidedly vulgar. According to his biography, he stopped publishing in one magazine after an editor asked him to make the horse go sober. Brooks died before the hit TV adaptation of “Mr. Ed” came out, in the sixties, but he likely would have disapproved of it. In the show, Mr. Ed had a puckish sense of humor but abstained from alcohol and no longer had a streak of nihilism. The palomino evinced a blithe, equine equilibrium.

A show that better honors the original spirit of Brooks’s tales is “BoJack Horseman,” the Netflix animated black comedy whose sixth and final season was released last week. It originated in 2011, when Raphael Bob-Waksberg, a struggling TV writer in Los Angeles, wrote an e-mail to his high-school friend Lisa Hanawalt, an illustrator living in New York City, with the subject line “BoJack the depressed talking horse.” Bob-Waksberg had been asked to bring ideas to a small animation studio that was pitching to Netflix, which had only just started acquiring original content; he and Hanawalt decided to team up to develop a show. Who knows if the streaming giant would pick up their absurdist idea today (last year, the platform cancelled Hanawalt’s “Tuca and Bertie,” a lovable show about friendship between a toucan and a songbird, after just one season). But back then Netflix needed content, and so a show about a talking horse named BoJack was born. Like the original Mr. Ed, BoJack drinks, cavorts, and misbehaves. The difference is that BoJack is not just an animal that talks like a man; he is anthropomorphized on a spiritual level, too, with more insecurities, anxieties, and troubles than many members of humankind.

“BoJack” was also, from the get-go, a brilliant Hollywood satire. Bob-Waksberg and Hanawalt set their show in “Hollywoo,” a technicolor, bizarro show-biz world in which animals and humans work together, fall in love, and screw each other over. In the pilot, we learn that BoJack (voiced by Will Arnett) is the former star of a saccharine syndicated comedy called “Horsin’ Around” (sort of a combination of “Full House” and “Mr. Ed”). He lives in a mansion in the Hollywoo Hills and has enlisted a human writer named Diane Nguyen (Alison Brie) to ghostwrite his memoirs. Diane is in a relationship with Mr. Peanutbutter (Paul F. Tompkins), a buoyant golden retriever and BoJack’s former television rival and current frenemy. BoJack has an agent named Princess Carolyn (Amy Sedaris), a pink tabby cat with a careerist streak, and a slacker house guest named Todd (Aaron Paul), who started sleeping on BoJack’s couch one day and never stopped. BoJack is also an addict: a drunk, a druggophile, a philanderer. He is existentially empty, full of bile and regret. He has no Wilbur Pope to talk to; Hollywoo is a packed zoo, but BoJack is alone in a self-made cage.

The show, in the course of six seasons, charted an ever-sinking series of rock bottoms. BoJack ruined the career of director after director, friend after friend. He visited an old flame in Santa Fe and ended up in bed with her teen-age daughter. He disappeared into a heroin haze with Sarah Lynn, the former child star of “Horsin’ Around,” and then Sarah Lynn had an overdose and died in his presence. BoJack choked a female co-star and then, in a moment of self-loathing, begged Diane to write a #MeToo exposé about his deeds. (She drove him to rehab instead.) “BoJack Horseman” was relentlessly bleak in its portrayal of depression, and of the unyielding and cyclical torment of living inside a troubled mind.

But, of course, no real animals were harmed in the making of “BoJack Horseman,” which is what kept it so fun to watch. Hanawalt’s candy-colored cartoons softened the show’s blows, as did the proliferation of sight gags and double-layered show-biz and animal jokes. When BoJack bombed a standup routine, he was met with the sound of literal crickets. A wolf walked through a party wearing a shirt that said “Sheep” on it. A socialite mouse—who at one point is Diane’s boss at a women’s Web site called “Girl Croosh”—wears a cardigan pin in the shape of two tiny cookies. A poodle woman shopping with her corgi gal pal is overheard saying, “I really shouldn’t eat chocolate, ’cause it can literally kill me.” If you wanted to, you could enjoy BoJack—at least for the first few seasons—for the densely clever visual environment Hanawalt and Bob-Waksberg created, where every frame feels like the fevered love child of a field guide and “The Player.”

Did Bob-Waksberg and Hanawalt know, from the beginning, how dark they’d let things get? “BoJack” ’s years on Netflix coincided with Hollywood’s broader confrontation with abuse and imbalances of power; they couldn’t have BoJack just float through Hollywoo ruining lives—particularly those of the women he encountered—without some sort of reckoning. In the show’s final season, BoJack does time in rehab, takes a job as a drama professor at Wesleyan, and, for a time, stays sober. But after a pair of reporters (a human man in a pin-striped suit and a pig in a wedding dress, speaking like lovers in a classic screwball comedy) discover BoJack’s hand in Sarah Lynn’s death, his new stability begins to crumble. He gives an apologetic prime-time interview to a mouse named Biscuits Braxby, which goes over more or less seamlessly. But because he is an addict—and a narcissist—he agrees to sit for a second interview, which goes horribly wrong. Braxby lays out all of the instances in which BoJack has manipulated and mistreated the young women in his coterie, and he turns defensive, then angry, then hangs his head in shame. BoJack is, finally, over in this town. He goes on a bender and breaks into a house he no longer owns, then falls into the house’s swimming pool and nearly drowns. Instead, the trespassing lands him in prison.

In the final scene of the series, BoJack, on a brief court-sanctioned day off from jail (being a celebrity, even a disgraced one, still has its perks), attends Princess Carolyn’s wedding. He has melancholy conversations with his former friends, all of which feel like final goodbyes. Watching this, I thought back on one of the show’s best episodes, “Fish Out of Water,” from the fourth season. In it, BoJack attends an underwater film festival, wearing a scuba bubble around his head that prevents him from talking. The episode is largely silent. BoJack cannot smooth-talk or equivocate. All he has are his actions, and he ends up spending much of the festival tenderly caring for a baby seahorse that has lost its way. The final season of “BoJack,” on the other hand, was exhausting in its verboseness. The protagonists were all, in their own ways, trying to talk their way to peace: BoJack in therapy and later on television; Princess Carolyn in her wheelings and dealings; Diane with a new partner (a buffalo named Guy); and Todd as he tried to reconcile his broken relationship with his mother. “BoJack” was not about a talking horse so much as it was about a horse who can’t stop talking—until he finally runs out of excuses. In the last seconds of the series, BoJack and Diane sit quietly together on a rooftop. If “BoJack,” in its long, strange, galloping run, has anything to teach us with its animal entanglements, it’s that there will never be easy solutions to the most vexing human problems. Sometimes the end of the story leaves you sitting alone, talking to a horse, unsure of what happens next.