I can’t decide if Nurse Diesel is the funniest screen character ever or the sexiest.

Also, I can’t decide whether I should have been so quick to admit that.

Oh sure, Nurse Diesel – with her mustache, strategic defense brassiere and Dick Cheney growl – is no Amanda Seyfried. But at least she has a pronounceable last name.

Diesel is easily the best thing about Mel Brooks’ “High Anxiety,” just as the woman who played her, Cloris Leachman, is usually the best thing about any project to which she attaches herself.

Leachman brings her autobiographical one-woman show to the Tibbits Opera House in Coldwater, Mich., on Tuesday. Call 517-278-6029 for more information.

Most of us could live twice as long as Cloris Leachman and not accomplish half as much as she has. The 84-year-old has made her mark on Broadway and in Hollywood, earning an Oscar, eight Emmys, one Daytime Emmy and a Golden Globe. That’s an impressive and reverential list, but Leachman said in a phone interview that she has always been and still is a girl who just wants to have fun.

Leachman was born on April 30, 1926, in farm country outside of Des Moines, Iowa. She had few friends growing up and liked it that way.

“The only reason I am able to play piano today is because nobody bothered me back then,” she said. “I had no distractions. Kids today do not have those advantages. I was by myself all the time and I loved it.”

So little did she know about boys, that when she went on her first double date, she observed them as an anthropologist might observe primates.

“I spent the whole date turned around watching the boys in the back seat,” she recalled. “I was trying to figure out how boys talk to each other. I feel like I am still learning how to do a lot of things.”

A church scholarship brought her to Northwestern University, which led to beauty and talent contests and more scholarships. Leachman eventually made it to New York where she navigated her way through the feeding frenzy that is an open audition to win the part of Nellie Forbush during the original run of “South Pacific.”

Roles in “Come Back Little Sheba” and “As You Like It” (opposite Katharine Hepburn) followed. She joined the famed Actor’s Studio where she discovered that she had already been doing many of the things Elia Kazan tried to teach her.

“Everything I had been doing naturally suddenly had a name to it,” she said. “Like sense memory, which is using objects to show emotion instead of putting everything on your face. I have always had success with that.”

Leachman said she admired Kazan but quit after Lee Strasberg took over.

“Kazan trained the most marvelous actors,” she said. “I stayed there two years. But Strasberg, I just didn’t like him so I quit. … He just raved about me and then spent about 20 minutes tearing down an actor who had worked on a hard scene; ... he tore that person apart and raved about me. ... I was so incensed that I quit.

“Besides, Rod Steiger was in class always crying about ‘God is dead’ and there was a lot of smoking,” she said. “I was just done with it.”

Some of the credit for her subsequent TV and movie careers has to go to an old-fashioned New York mugging. Her then-husband, George Englund, was so shaken up after being held at knifepoint in an elevator that the family decided to move permanently to the West Coast, Leachman said.

After many dues-paying years doing guest shots on shows like “Twilight Zone” and “Rawhide,” Leachman earned the role of Phyllis Lindstrom on “The Mary Tyler Moore Show.” She said she did not play the character as written.

“It said she was neurotic and I didn’t get any fun out of that,” she said. “That didn’t say anything to me. So I decided that she was the perfect person: the perfect chef, the perfect chauffeur, the perfect psychologist, the perfect friend and the perfect slut in the bedroom. How boring is that?”

During a break after production wrapped on that show’s first season, Leachman joined the cast of Peter Bogdonovich’s “The Last Picture Show.” It was while Bogdonovich was filming Leachman’s last scene that the director made a top-notch prediction.

“They shot a take and I said, ‘Do you want to do it again?’ and he said, ‘No you’re going to win an Academy Award for that one.’ I said, ‘Uh huh, sure. Are you ever dreaming.’ ”

Of course, Leachman did go on to win the best supporting actress award for her work in the film at the 44th Academy Awards.

Leachman said she wanted to save her stories about working on Mel Brooks’ films for the Coldwater show, but she did talk about how Brooks’ first came to be aware of her. It involved a guest spot on a TV variety show (Leachman can’t recall which one). She rehearsed a skit with Tony Randall that involved Leachman milking imminent childbirth for comic effect.

“The writer kept coming on and saying, ‘You’re stealing the show.’ And I said, ‘I have five children, so I sure know how to have labor pains.’ The writer was Mel Brooks.”

Many years later, Leachman would infamously challenge Brooks to a boxing match when he would not cast her as Frau Blucher in the stage version of “Young Frankenstein” because he thought she was too frail. Leachman said she was extremely ill during her audition.

“I didn’t know if he knew how sick I was,” she said.

Brooks later relented when he saw Leachman in “Dancing With the Stars,” but the show closed before she could join it.

Of late, Leachman has become known for flamboyant behavior unbecoming (in some people’s view) of an octogenarian. She has posed semi-nude several times, danced in a TV competition usually reserved for celebrities half and one-quarter her age and provided unexpurgated exegesis on the alleged shortcomings of Betty White, Jennifer Lopez, Joan Collins and Marlon Brando.

Leachman said she never does anything for effect or shock value.

“I just do what I like to do,” Leachman said. “I don’t feel like I have to prove anything to anybody.”

The next thing she’d like to do, she said, “is play (Gershwin’s) ‘Rhapsody in Blue’ with a very fine American orchestra.”

The only other person in her hotel room when she said this was her son George, who is also her manager. George was hearing it for the first time, she said.

Asked what his reaction was, Leachman replied, “I would describe it as a ‘What the (expletive)’ expression.”