He was 10 inches tall, with blond hair, bright blue eyes, oversized ears like Mickey Mouse and the rosy cheeks of a child who had played too long in the snow. His name, Topo Gigio, was Italian for Louie Mouse, and during his dozens of appearances on “The Ed Sullivan Show” in the 1960s and early ’70s, he seemed, indeed, to be a cartoon mouse sprung to life, touched with Blue Fairy magic like Pinocchio.

In recurring sketches with Sullivan, he scampered on two legs, wiggled his ears, rolled his eyes, poked fun at the variety show host and pulled up the covers on his tiny bed. When Sullivan once greeted him with a kiss on the cheek, he cartwheeled into a handstand and kicked his legs with delight — astounding millions of viewers who tried in vain to spot any strings or wires controlling his movements.

“The first thing everyone wants to know is how does Topo Gigio work,” Sullivan told Popular Science in 1967. “Even after all the times I’ve worked with that darn little mouse,” he added, “I sometimes forget he isn’t real.”

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The bubbly, childlike mouse was part puppet, part marionette, created by Italian puppeteer Maria Perego, who was awarded a patent for her design and operated Topo with the help of one or two other performers, plus a voice actor. She was 95, and working on a new Topo Gigio series for Italian television, when she died Nov. 7.

Her death was announced by her lawyer Alessandro Rossi, who did not give a precise cause but told the Italian wire service ANSA she had fallen ill at her home in Milan.

Ms. Perego had experimented with papier-mache and plaster before using a soft, smooth foam to create Topo Gigio in 1959 with support from her husband, Federico Caldura. Her character appeared on Italian television programs before spreading to Swiss, German, Dutch and Spanish programming, eventually becoming a hit in Japan and a staple of “The Ed Sullivan Show” in the United States.

“I suppose in the 18-year history of our show we’ve never had any star who’s won such affectionate acceptance as our little Italian mouse, Topo Gigio,” Sullivan said in one 1967 episode, years after his program helped introduce audiences to Elvis Presley and the Beatles.

The host reportedly hired Ms. Perego after seeing a tape of one of her Topo Gigio performances in Europe, resulting in a string of 94 appearances from Dec. 9, 1962, until the program’s final episode on June 6, 1971, according to the official Ed Sullivan and Topo Gigio websites. Almost every appearance ended with a request from Topo: “Eddie, kiss me good night.”

While Sullivan was sometimes criticized for having a stiff stage presence and wooden delivery, he seemed to loosen up while talking with Topo Gigio, voiced by Italian actor Peppino Mazzullo. The pair discussed modern art, Topo’s love for spaghetti and lasagna (as well as gefilte fish and chow mein), and the intricacies of show business.

“How long, Topo, do you think you’ll last in television if you can’t sing or dance or act?” Sullivan asked in one episode. The puppet replied, “Eddie, how long have you been on the air?” — leading Sullivan to retort, “Topo, nobody likes a smart aleck mouse.”

In his book “Impresario: The Life and Times of Ed Sullivan,” biographer James Maguire credited Ms. Perego’s character with helping to broaden Sullivan’s appeal to younger viewers, enabling the television host to display a gentler, more endearing side of himself.

“On its face the Topo-Ed act was a contradiction,” he wrote. “Here was Ed, a man whom his critics (and even friends) had called every variation of stiff, who had cursed and elbowed his way to stardom, burning through an ulcer, yet onstage with Topo he was a sentimental ball of sweetness, being childlike for a live audience of forty million viewers. . . . Topo opened him up.”

Ms. Perego remained almost entirely out of view even as her character became famous around the world, singing alongside Louis Armstrong, Frank Sinatra and Italian star Raffaella Carrà. For most performances, she used two fingers on her left hand to control Topo’s legs; with her other hand, she operated a clothespin-like system to open and close his mouth. One or two other puppeteers would control his arms and hands through a set of rods, depending on the complexity of the scene.

All of the puppeteers wore black velvet robes, using gloves and hoods to conceal themselves in front of a black background that rendered them invisible to viewers. And while Ms. Perego wrote many of the Topo stories, her character’s “Ed Sullivan Show” appearances were also developed with help from other writers — notably comedian Joan Rivers, who was less appreciative of Topo than many of the show’s young viewers.

“I lay on the floor and wrote a sketch about this comic Italian puppet mouse, with a little Italian accent, who had become a semi-fad in America,” she recalled, according to Sullivan’s website. “I had him asking Ed Sullivan to explain football. I put Topo in a little football jersey that said ¼ on the back. Topo Gigio paid my car payments for six months. God bless that little lousy mouse.”

Ms. Perego was born in Venice on Dec. 8, 1923, and by the mid-1950s was working as a puppeteer with the Italian public broadcaster RAI. She invented characters such as Picchio Cannocchiale, a riff on Woody Woodpecker, and traced her puppetry breakthrough to a Christmas tree she spotted in a barbershop window, made from a piece of green sponge.

She began using the material for puppets, while slowing down and speeding up records to get new ideas for characters and situations, including “insects, fish, singing flowers, cactuses with large sombreros and [guitar]-imitating Mariachis,” according to her Topo website.

Topo began to take off in 1961, appearing in Italy that year on the popular TV program “Carosello” and in a film, “The World of Topo Gigio,” co-directed by her husband. “Put it all down as a nice treat for the kiddies,” wrote New York Times reviewer Howard Thompson. “And while we’re at it, who says a mouse can’t act?”

Her character later starred in a 1967 Japanese movie, “Topo Gigio and the Missile War,” by celebrated filmmaker Kon Ichikawa, and appeared in comic strips and magazines.

Ms. Perego continued working on him until her death — information on survivors was not immediately available — and said she saw Topo as “a naive character,” with shades of Don Quixote and Charlie Chaplin’s Little Tramp.

“With his optimism he tries to justify himself, to invent, to introduce himself and to enter into fantasy and the absurd,” she said recently on the Italian television program “Le Ragazze.” “He’s always on the edge between imagination and reality.”