Daniel Dumile, the masked rapper who performed as MF Doom and built a lasting underground fan base with his offbeat wordplay and comic-book persona, died on Oct. 31, a statement from his family said on Thursday. He was 49.

The rapper’s record label, Rhymesayers, provided the statement, signed by Mr. Dumile’s wife, Jasmine. The label did not give the cause of death or say why it was being announced two months later.

Over six solo albums released between 1999 and 2009 and five collaborative LPs (with Madlib and Danger Mouse, among others) between 2004 and 2018, Mr. Dumile honed a style that was intricate and imaginative, calling on both esoteric and lowbrow references as well as cartoonish imagery in lyrics that could be poignantly emotional.

Born in London and raised on Long Island, he grew up steeped in early hip-hop. He debuted in 1989 on the 3rd Bass track “The Gas Face” with a standout cameo that helped him get a record deal for his own group, KMD, in which he rapped as Zev Love X.

The act included his brother, Dingilizwe, who performed under the name DJ Subroc. Its first album, “Mr. Hood,” arrived in 1991 on the major label Elektra. During the recording of KMD’s second album, “Black Bastards,” Subroc was killed in a car accident, and the label later declined to release the record. Mr. Dumile vanished from the entertainment business but continued to work on music privately while he raised his son.

He resurfaced in 1997 with the single “Dead Bent,” his first song under the name Metal Face Doom. (The persona was a nod to the Marvel villain Doctor Doom.) Around the time of the release of the album “Operation: Doomsday” in 1999, which featured a masked character on its cover, Mr. Dumile began hiding his face in public, at first with a stocking mask and later a metal one, which became his signature.

In a 2009 interview with The New Yorker, he said the mask had become necessary when he made the leap from the studio to the stage. “I wanted to get onstage and orate, without people thinking about the normal things people think about,” he said. “A visual always brings a first impression. But if there’s going to be a first impression, I might as well use it to control the story. So why not do something like throw a mask on?”

Once an underground cult figure, Mr. Dumile found greater fame with albums in the mid-aughts. “Madvillainy,” which arrived in 2004 with the producer Madlib, was a breakthrough.

“He delivers long, free-associative verses full of sideways leaps and unexpected twists,” the critic Kelefa Sanneh wrote in reviewing a 2004 concert in The New York Times. “You think you know where he’s heading and what each sentence will mean when it ends. Then it bends.”

On “Raid,” a track from “Madvillainy,” he rhymes:

Trippin’, to date the Metal Fellow been rippin’ flows
Since New York plates was ghetto yellow
With broke blue writing, this is too exciting
Folks leave out the show feelin’ truly enlightened

Released in the same year, his album “MM .. FOOD” (an anagram of his stage name) included tracks like “Gumbo,” “Kon Queso” and “Kon Karne.” In rapping about the seemingly mundane topic of food with goofiness and wit, he was “showing respect for human life,” he told Spin in 2004.

“I’m more like a writer dude rather than a freestyler,” Mr. Dumile told The Chicago Tribune that same year. “I like to design my stuff, and I consider myself an author.”

Mr. Dumile rapped under different personas and later became known for sending impostors out onstage to perform for fans; in his trademark metal mask, it was difficult to know the difference. The body doubles often disappointed fans but sparked viral moments online, like when an apparent MF Doom drop-in at a concert turned out to be the comedian Hannibal Buress.

In 2017, Mr. Dumile announced on social media that his son, King Malachi Ezekiel Dumile, had died at 14. Information on survivors was not immediately available.

Though he never reached mainstream superstardom, Mr. Dumile was widely admired by fellow rappers and producers. He was “your favorite MC’s MC,” wrote Q-Tip from A Tribe Called Quest on Twitter. In a post on Instagram, El-P wrote: “thank you for keeping it weird and raw always. you inspired us all and always will.”

Caryn Ganz contributed reporting.