In “Morbius,” Jared Leto sports his signature beard and long silky black hair parted down the middle, though for a good stretch he doesn’t give off his usual Jesus of Beverly Hills glow. That’s because he plays the sickly Dr. Michael Morbius, who is cadaverous and sunken-eyed, hobbling around on a pair of forearm crutches. Morbius, a science wizard, has spent his life trying to come up with a cure for his mysterious ailment; along the way, he invented artificial blood. But now he’s going for broke. In the film’s opening sequence, he emerges from a helicopter in the mountains of Costa Rica and enters a cave to capture a gigantic flock of vampire bats, whose DNA he plans to extract to create a powerful new serum, which he’ll inject into his own mottled veins.

It’s an experiment at once bold and beyond the pale, in direct violation of medical ethics, which is why he conducts it on a cargo ship off the coast of Long Island, with eight mercenaries in tow. It is also, of course, an experiment destined to go very, very wrong. In Marvel movies like the ones featuring the origin stories of the Hulk or Captain America, these kinds of experiments tend to blow up in spectacular, mind-and-body-bending ways. But in “Morbius,” there’s not much ado about what happens to Michael Morbius. Working with his loyal assistant, Dr. Martine Bancroft (Adria Arjona), he injects the serum and instantly morphs into a thirsty kinetic vampire, his skin stretched over his cheekbones, his teeth a gallows row of pointy incisors, his pupils scrambled like Jackson Pollock pinpoints.

Even if you’re not familiar with the “Morbius” comics, which first appeared in 1971, we’ve seen monsters like this one many times before ­— in “The Reptile” (1966) and old Tobe Hooper films, and in movies I can hardly think to name because the whole feral chompy look and gnashing vibe of Morbius the vampire supervillain and brooding antihero, while true to the comics, has a generic demon flavor to it. The entire movie, directed by Daniel Espinosa from a script by Matt Sazama and Burk Sharpless, is generic — naggingly, almost jarringly so. You watch it and think, “This is what now passes for a new Marvel chapter?”

Technically, “Morbius” is the third entry in the Spider-Man Universe, after “Venom” and “Venom 2: Let There Be Carnage”  — you know, the movies that that were designed to reignite the comic-book spirit at Sony Pictures after the two plodding Andrew Garfield “Spider-Man” installments. And just as the executives at Sony seemed to unleash those earlier films upon the world without the kind of creative oversight that might have enlivened them, “Morbius” is a movie in which it’s clear that no one ever sent the script back for a rewrite with the instructions, “Please add a script.” As in: Add spice, add dialogue, add something so that the movie plays like more than a barely colored-in diagram.

“Morbius” isn’t even a debacle. It’s a little over 90 minutes long if you don’t count the credits (which include what has to be the worst closing teaser I’ve ever seen in a Marvel movie — it ends with the word “Intriguing,” dangled as if Vincent Price had uttered it), and for all the overwrought push of Jon Ekstrand’s score, the film is nothing more than a flimsy time-killer, an early-April placeholder of a movie. It’s as trashy and underimagined as the “Venom” films, though it’s easy to see why both of those became mega-hits: The character of Venom, who’s like a superhero merged with the creature from “Alien,” with a voice of basso showbiz effrontery, is an entertaining hunk of sci-fi demon eye candy. Whereas Leto’s teeth-baring monster-scientist truly looks like a relic from the ’70s. He never scares or dazzles or haunts you — not because Leto is less than a good actor, but because this isn’t a character based on acting. It’s based on the creakiest FX, the one (mild) exception being the painterly trails of digital “smoke” left behind by Morbius as he flies through the air.

At first, Morbius has no control over himself. He makes mincemeat of the mercenaries, which brings a couple of cops, the earnest Stroud (Tyrese Gibson) and the cutup Rodriguez (Al Madrigal), onto his tail. Are they investigating a criminal mystery? Not really. A mystery requires at least two moving parts. But Morbius, though he now needs blood to sustain him, doesn’t want to be a killer; that’s his torment. For a while, the packets of artificial blood that hang in his laboratory freezer work just fine. Leto will grab and drain one like a desperate alcoholic in a ’40s movie downing a pint of whiskey. But the effect of the artificial blood starts to wane. First it works for six hours, then for four hours and 22 minutes. What will happen when it stops working?

Before he has to worry about that, Morbius must deal with Milo (Matt Smith), his sickly British boyhood chum from a sanitarium in Greece, which was overseen by the kindly Emil Nikols (Jared Harris). The once-mild Milo, after too much bullying, has grown up into a bitter martini-swilling aristocratic shut-in. Unlike Morbius, he has no compunction about not only taking the serum — which he does behind Morbius’ back — but giving into his newly enhanced virile bloodsucker self. Matt Smith, from “Doctor Who” and “The Crown,” gives Milo a toxic magnetism. There’s a sequence that begins promisingly, with Milo dressing and strutting in front of the mirror then heading to a bar, where he suddenly feels like a superman. The movie needed more of this (and juicier writing even in that bar scene). Matt blasts in and out of demon face at will, and his embrace of a newly empowered state is, frankly, more fun than Jared Leto’s pensive guilt about it.

These two rise in tandem, then face off, and that’s more or less the entire movie. The character of Morbius is being set up as one of Spider-Man’s antagonists, which the film establishes with a late-in-the-game appearance by Michael Keaton’s Adrian Toomes. Of course, this isn’t Leto’s first fling with comic-book villainy, but his Joker, in “Suicide Squad,” displayed the actor’s talent as well as his genuine attraction to preening dark-side souls. “Morbius” is more like a paycheck movie: time for Leto to punch the clock and get on the comic-book train. But this reluctant vampire has so little flavor that he’s closer to the invisible man.