As an admittedly elder millennial, my first encounter with Tim Curry was not his defining role — not for most people, at least. His delicious, lascivious Dr. Frank N. Furter in “The Rocky Horror Picture Show” may be the Curry performance that takes up the most real estate in the imagination once you get around to seeing it; a certain bracket of still-haunted Gen-X viewers may argue for his original Pennywise in the TV miniseries “It” on that front.

But for kindergarten-age me, Curry announced himself and his flamboyant gifts in a far more modest enterprise: the shabbily budgeted 70-minute British television adaptation of Jill Murphy’s children’s book “The Worst Witch,” a kind of pre-Potter magic-academy romp with much less complicated lore. For the most part, it’s innocuous, sweet-natured kids’ entertainment, even if 21st-century tots might be bewildered by its chintzy-even-for-the-’80s effects and the spirited stage-school performance style from much of the ensemble (including a pre-teen Fairuza Balk in the lead). For a full five minutes, however, it operates on a higher level — when Curry swoops into proceedings as the Grand Wizard Egbert Hellibore, and delivers a catchy little ditty called “Anything Can Happen on Halloween.”

Musically and lyrically, it’s not exactly Sondheim: “Anything can happen on Halloween/A dog can turn into a cat,” he croons, over clunky mid-’80s synths. But Curry, swirling a voluminous pink satin cape and baring his famously, fabulously imperfect pearly whites, sings it with full-tilt drama and snarling conviction, barely suppressing a wink at his young audience as he promises them that, on October 31st, “your blood begins to run.” It’s a performance of Broadway-scale theatricality and cabaret wit oddly slotted into the world of daytime children’s TV; I was mesmerized, even if I couldn’t altogether explain why.

Later, I realized this was one of my first encounters with outright camp: that hard-to-articulate but immediately knowable balance of artifice, earnestness and irony that can make high art of pop art, and vice versa. And when, years later, I eventually saw “The Rocky Horror Picture Show” — at a still-tender age, old enough to thrill to its color and danger, and young enough to miss all manner of innuendo — I could draw a straight (or not-so-straight) line between what Curry did in that perky Halloween earworm and the taboo-busting explosion of genderqueer polysexuality that he brought to Jim Sharman and Richard O’Brien’s landmark adult musical. The latter film was shooting for outrage and all-time cult status; the former, to amuse grade-schoolers for a little over an hour. Curry’s great, generous gift as a performer was that he brought equal energy and enthusiasm to both.

It wouldn’t be altogether correct to call Curry’s performance in “The Rocky Horror Picture Show” a revelation. It was, after all, a screen transfer of what he had already achieved on stage in London, Los Angeles and, briefly and unsuccessfully, on Broadway: Going in, the filmmakers knew exactly what kind of lightning in a bottle they had, as did any of those lucky early-doors theatergoers. But who else could have possibly known what to expect?

Even when you watch the film for the umpteenth time, Curry’s entrance is always a jolt. Sporting a drag queen’s beat and Queen Elizabeth’s diction, his Frank N. Furter arrives somehow as an extra-subversive presence in what is already a joyfully anarchic affair: At once beautiful and grotesque and frightening and rampantly sexy, he belts out his rock ‘n roll-infused showtunes with militaristically rehearsed precision, all while making his fetishwear-clad body a supple, spontaneous, unpredictably sensual instrument. He hits his every mark but blurs every other line, setting out to make viewers of all genders and sexualities suddenly confused about what they desire. Queer cinema doesn’t have many totemic, standard-bearing icons of alternative sexuality on this scale, and certainly none that have permeated the popular consciousness to quite such an extent. All revival performances can only feel like a tribute act: In 2016’s inevitably lesser TV remake, a game Laverne Cox seemed to be playing Curry first and Frank N. Furter second.

As a screen presence, meanwhile, Curry landed so fully formed in “The Rocky Horror Picture Show” that it’s easy to forget it was his film debut — among the most declarative in cinema history, surely, but also near-impossible to follow up. Curry must have known that: In the years after that astonishing breakout, he was wise to remain active in theater and television, rather than putting all his chips on a movie career. A couple of supporting roles came and went before his next film splash, as the sociopathic sleazabag Rooster in John Huston’s megabudget musical “Annie”; the film was a bloated disappointment, but his nasty, vinegary chemistry with Carol Burnett’s Miss Hannigan was a highlight.

By the mid-’80s, with “Rocky Horror”-style provocations long out of fashion, he’d worked out his natural place in the industry: to reliably deliver a streak of ripe, strange camp to less risky projects. Those included his nightmare-fuel turn, under demonic prosthetics, as Darkness in Ridley Scott’s adventure “Legend,” or comic mugging in more recognizably arch mode as the butler Wadsworth in the gimmicky board-game spinoff “Clue” — a less likely cult touchstone than his debut film, but a surprisingly enduring one.

If his terrifying but still flagrantly theatrical Pennywise in the original TV adaptation of “It” launched a million clown phobias and sealed his place in the post-“Rocky Horror” pop-culture firmanent, he’d never find another signature role. The ’90s mostly confined him to enjoyable rent-a-villain duty, the preserve of many a posh-accented British thespian of the era: He sneered and leered through the likes of “The Three Musketeers,” “Congo” and “Charlie’s Angels” with good grace and good humor, and did significantly more than the minimum as a hilarious Long John Silver in “Muppet Treasure Island,” bringing exactly the right pantomime spirit to proceedings. For a generation of kids slightly younger than me, that might have been their introduction to the actor, and it wouldn’t have been a half bad one: knowingly absurd, committedly entertaining, defiantly camp. For while Hollywood, it’s fair to say, never made the most of Tim Curry, he made the most of everything he got.