In the fall of 1984, the world was introduced to the actor Malcolm-Jamal Warner, playing Theodore Huxtable in “The Cosby Show.” In the very first episode, the teenager was confronted by his father (played by series creator Bill Cosby) about his lagging grades and how they might affect his college aspirations. Eight years later, after the show became a cultural touchstone, the series ended with Theo getting his college diploma. In between, viewers saw Warner and the character he portrayed grow up onscreen. The somewhat wayward yet wholly relatable teenager became an accomplished young adult, a crucial figure in the then-rare depiction of a professional Black American family.

Theo’s journey was at the heart of the show. (A show that, in recent years, has been tainted by the many sexual assault allegations leveled against its creator.) Here are some of the memorable scenes involving the character played by Warner, the actor who died from drowning on Sunday at the age of 54.

Warner stood out from the beginning of the show. In the pilot episode, when Cosby’s Dr. Cliff Huxtable speaks to Theo about his grades, he responds with an impassioned plea: “Maybe you can just accept who I am and love me anyway. Because I’m your son.” The studio audience offered hearty applause as Theo looked away from his father. But “The Cosby Show” proved it was a different sitcom by not ending the scene. Instead, Cliff takes a beat, stands up and says, “Theo, that’s the dumbest thing I’ve ever heard in my life!”

“I am your father,” he continued, issuing a line repeated by many parents around the world: “I brought you into this world, and I’ll take you out.”

Later in the first season, Warner flexed amazing comedic timing for a 14-year-old. In “A Shirt Story,” Theo purchases a costly shirt by the fictional designer Gordon Gartrell to impress a date. Cliff bemoans the top’s $95 cost and takes it from his son with the intention of returning it. Theo then turns to his sister Denise (played by Lisa Bonet) to craft him a facsimile of the shirt. The result is disastrous, and it’s worth watching Theo’s incredulous reaction to Denise’s non-handiwork. Her bright yellow creation features mismatched sleeves and an ungainly collar. And when Denise suggests that the it would look better more tucked in, Theo responds, “It’s tucked into my socks!”

However, all ends well for Theo. Cliff reveals that he had never returned the original shirt, and Theo’s date is impressed with Denise’s outlandish design.

Lisa Bonet and Malcolm Jamal-Warner on “The Cosby Show.” Credit…NBCU Photo Bank/Getty Images

Theo and Denise are a little too joyous while describing getting into a car accident on an icy road. The reason? It was Stevie Wonder’s chauffeured car that collided with theirs.

“It was just a matter of being in the right place at the right time,” Theo explains.

Wonder invites the Huxtables to his studio as a way of patching things over. Questlove, the musician and filmmaker, described the episode as eye-opening in his memoir, “Mo’ Meta Blues: The World According to Questlove.”

“At one point Theo says ‘jammin’ on the one,’ and before you knew it, Stevie Wonder had sampled it and inserted it into a song,” Questlove wrote. “It’s not an exaggeration to say that this episode was the incident that truly sucked me into hip-hop production. It was the first time I saw anything like that, and I’ve surveyed the rest.”

In the fourth season, Theo and his friend, Walter (nicknamed Cockroach, played by Carl Anthony Payne II) complain about studying Shakespeare in school, so the students translate Shakespeare’s early modern English into a more easily digestible hip-hop song. Warner entertainingly delivers the rap in a scene that depicts the generational gap between father and son.

A medical professional suggests that Theo has dyslexia during the sixth season of “The Cosby Show.” The diagnosis explains that Theo’s school struggles were not caused by a lack of ambition, as Cliff once believed. “I know what I want to say, but I have a hard time getting it straight in my mind,” Theo says in the episode. The affliction prompts Cliff and his wife, Clair (played by Phylicia Rashad), to be more sensitive in their parenting. Outside the show, the story line raised awareness and understanding of dyslexia.