Kid Cudi is the latest celebrity being called to testify at Sean “Diddy” Combs ′ sex trafficking trial in New York.

The popular melodic rapper is expected to take the stand Thursday and tell the jury about his brief relationship 14 years ago with Combs’ ex-girlfriend, the R&B singer Cassie.

According to court filings and testimony, the Cassie-Cudi relationship, which grew out of the two working on music together, sent Combs into rages in which he beat her. Prosecutors contend that Combs was so upset he arranged to have Cudi’s convertible firebombed.

Combs has pleaded not guilty to charges that he leveraged his status as a power broker to abuse women.

Here’s what you need to know about the 41-year-old Cudi, whose legal name is Scott Mescudi.

Who is Kid Cudi?

The Cleveland born-and-raised, skinny-jean wearing, Grammy Award-winning rapper has long been celebrated for his alternative hip-hop, emotional music that effortlessly weaves genres together in surprising ways.

Music blogs and other tastemakers quickly caught on to Cudi's 2007 single, “Day ‘n’ Nite,” with its unique singsong style that later appeared on his blockbuster 2009 debut, “Man on the Moon: The End of the Day” as “Day ‘n’ Nite (Nightmare)." The album's hits included “Pursuit of Happiness (Nightmare)” and is easily one of the most influential rap records of the last two decades. In September, “Day ‘n’ Nite” was certified diamond by the Recording Industry Association of America.

Cudi began as something of a protege of Kanye West, when the then-uncontroversial rapper signed Cudi to his G.O.O.D. Music label in 2008. Cudi left in 2013.

He is featured on Jay-Z's “The Blueprint 3” and West's landmark “808s & Heartbreak.” Cudi has always had an eye and ear toward innovation. In 2022, his album “Entergalactic” was released alongside a Netflix adult-animated romantic comedy of the same name, which he told The Associated Press allowed him to “explore the abstract.”

What is Kid Cudi’s involvement with Combs and Cassie?

Cassie, whose legal name is Casandra Ventura, has been the trial’s central witness with her accounts of years of violence and sexual abuse.

She testified that Combs arranged for her to meet Cudi in 2011 to work on music. The two began dating soon after, and she said she got a burner phone to communicate with Cudi in secret.

Cassie said she and Combs had broken up at the time, although they still engaged in sex parties that Combs orchestrated. It was during one of these that Combs looked at her phone and learned of the Cudi relationship, Cassie testified.

In response, she said he lunged at her with a corkscrew and kicked her in the back.

When Cassie and Combs were out of the country in 2012, Combs told her that Cudi’s car would be blown up and Combs wanted Cudi’s friends there to see it, Cassie testified.

On Tuesday, Cassie’s mother, Regina Ventura, testified that Cassie told her Combs was so angry about her relationship with Cudi that he planned to release sexually explicit videos of her and send someone to hurt Cassie and Cudi.

Cassie testified that Cudi came to visit her at her mother’s Connecticut home around Christmas in 2011 and she broke up with him, fearing for both of their safety.

The Associated Press does not typically name people who say they have been sexually abused unless they come forward publicly, as Cassie has.

Kid Cudi's more recent music, and acting

His latest album, “Insano,” arrived last year. Soon after its release, “Insano (Nitro Mega),” a partner record that featured Wiz Khalifa, Pusha T, Steve Aoki and more, arrived.

On May 9, Cudi released his latest single, “Neverland.” A short film of the same name, directed by Ti West and produced by Monkeypaw Productions, will premiere at Tribeca Film Festival this June.

Also in May, Cudi officially launched his new apparel label, WZRD.

Daring fashion has been a longtime passion for Cudi; the rapper has partnered with brands such as BAPE and Adidas. He collaborated with the late designer Virgil Abloh, and in 2021 channeled Nirvana frontman Kurt Cobain by wearing an Abloh-designed Off-White floral dress on stage at “Saturday Night Live.”

Last week, he announced his engagement to menswear designer Lola Abecassis Sartore.

Cudi is also a celebrated actor, having appeared in a number of feature films and television programs. They include 2020s “Bill & Ted Face the Music,” the 2021 Netflix original “Don't Look Up,” the HBO series “How to Make It in America” and the glossy “House Party” remake in 2023, in which he played it straight as an anti-social lurker who doesn’t like parties (“too much laughing”) and only wanted to go to give his pal LeBron a poem, as The Associated Press' Lindsey Bahr wrote in her review.

What to know about Kid Cudi, the rapper testifying against Sean ‘Diddy’ Combs