Ronda Rousey is celebrated as a trailblazer, the first female champion in the male bastion of the Ultimate Fighting Championship. She got there by herself, with nothing more than the assistance of her mom and a few select others.

When she enters the octagon tonight at Honda Center in Anaheim, Calif., for UFC’s first female fight — the main event against challenger Liz Carmouche — Rousey does so only after taking a series of boldly independent stances that wove together the fabric of this Santa Monica high school dropout.

“I don’t know if I’d call myself the coolest chick ever,” Rousey said before a conditioning and sparring session at a friend’s Glendale gym.

“I knew that I liked what I was doing, that it was what I wanted to do for a living, and that the profession didn’t really exist so much.

“So I had to create it. When I was thinking of my options — go to school, do whatever jobs — I didn’t like any of them. So I was like ‘I could make this happen somehow.’ I don’t think of myself as extra cool or extra-pioneering…. I’m just too stubborn to fit into whatever molds were ever there.”

As a mixed martial arts fighter, Rousey, 26, has leaned heavily on the base of the judo schooling she received in becoming the youngest U.S. Olympic entrant in the discipline at age 17 in 2004, and the first American female medalist by winning a bronze in Beijing in 2008.

Her ability to manhandle opponents, get them to the canvas and torture them by turning their arms into unbearable positions has made her 6-0 with six first-round submissions by armbar.

The destructive run was so impressive it caught the attention of UFC President Dana White, once reluctant to bring female fighters into the sport that caters to an ultra-male, rough-around-the-edges crowd.

“She willed herself here; it’s why I just declared her the UFC women’s champion,” White said. “She’s bad-ass, and I know people are saying it’s because she’s cute, or because I have a crush on her. No, it’s because she inflicts pain. She’s mean, nasty and likes to finish people.

“I have said the women’s talent pool is not deep enough, which got people to suggest this is the Ronda Rousey show. You’re right, it is. I brought her in here because I think she can do it. It takes a certain type of person, personality and fighter to appeal to everyone. And she’s got it.”

That “it” factor is the product of a life fraught with challenges, even from birth in Riverside County when the umbilical cord wrapped around Ronda’s neck and deprived her of oxygen, leaving her effectively unable to communicate verbally for years as she underwent speech therapy.

“She couldn’t talk, you couldn’t understand her, she couldn’t get the words out,” Rousey’s mother, Ann Maria Rousey DeMars, said.

Around age 4, Rousey’s parents told her she could have anything she wanted for her birthday, so she asked for what she pronounced as a “balgren.”

“We dragged the three girls across Riverside and L.A. County to all the toy stores looking for this ‘balgren,’” Rousey DeMars said. “Finally, we find the biggest Toys R Us store we can find, my husband grabs the manager and says, ‘I don’t know what a balgren is, but you need to find it, because we’re not leaving here until you do.’”

Through a process of elimination and great patience, the manager translated that Rousey was in search of a Hulk Hogan wrestling buddy toy.

A major outlet for the frustration over her speech problems was sports. Rousey swam, entered track and field meets and was highly competitive with her bigger sisters, Maria, now 30, and Jennifer, 27.

The Rouseys moved from California to North Dakota when Ronda was entering grade school, but they would return to Santa Monica when she was 8, with her mother as the only parent.

Rousey’s father, Ronald, an aerospace worker, had committed suicide, which the family says was triggered by a broken back that exacerbated a hemophilia-type condition he had.

Ronda was shy and self-conscious in public. She cut her hair short, wore baggy clothes as a young teen and went by “Ronnie.” Inside the home was a different story, where the sassiness was alive.

Her mother likes to tell the story of when Ronda spit in the face of sister Maria. Upon being told she was being grounded because she had specifically been told not to hit her sister, Ronda’s defense: “I shouldn’t be grounded because you didn’t tell me specifically not to spit in Maria’s face,” Rousey DeMars recalled.

Around then, Rousey found judo, inheriting skills her mother carried as a former Pan American Games qualifier in the sport.

Rousey DeMars would drill self-confidence and high expectations into her daughter as they drove some 14 hours a week to various judo training centers.

“One of the things I’ve always believed is not to be defined by other people’s expectations,” Rousey DeMars said.

One of those was Ronda’s Spanish teacher at Santa Monica High, who was unhappy with Rousey’s request to miss extensive school time as a sophomore to participate in an Olympic-qualifying judo competition. Rousey responded to the teacher’s displeasure by dropping out.

In 2005, she found herself temporarily homeless, living out of her Honda Accord. She was working at a 24 Hour Fitness, where she leaned on the benefits of her $50 monthly membership to train and shower and save up for a rent deposit. She was also working as a judo teacher and veterinary assistant.

“Of course I was scared,” Rousey said. “I was failing in life. There was a long time I had no job security, no options and no education. But in dropping out to go after judo, I had already decided, ‘It’s not the only way, and, yeah, it’s going to be a lot more difficult — the unbeaten path is a lot more bumpy.’ But it’s still a way to get somewhere.”

Rousey made it to Beijing in 2008, and left with her bronze medal and little else, deciding then to pursue an MMA career, much to her mother’s chagrin.

Rousey Demars told her daughter, “There’s no future in that, there’s no women’s MMA,” to which Ronda said, “Give me a year.”

She made her pro debut at a King of the Cage event in Tarzana on March 27, 2011, landed in the more elite Strikeforce organization by August of that year, and was Strikeforce champion on March 3, 2012, beating her self-imposed deadline.

“Her attitude is the thing that does it for her,” said Rousey’s longtime friend and UFC fighter Manny Gamburyan. “She’s a girl with a mentality like a guy. She knows what’s up. She’s a very hard worker, and if she knows she’s on to something that will help her, she works on it constantly.”

That single-mindedness has created a life for Rousey in which many of her best friends are male Armenian MMA fighters in Glendale. She hails her skills as a “wing woman” in helping them find girls at night spots.

As for Rousey’s own dating, her mom says, “That can be trial and error for some. For Ronda, it’s all error.”

If anyone does something to seriously rile Rousey, “Ronda holds a grudge like nobody’s business,” her mom says.

“I had to make a rule: If it happened over a year ago, you can’t bring it up anymore. She’ll be in a fight and say, remember when Maria wore my shirt and stretched it out … and I say, ‘You were 8!’

“She’s also loyal to a fault. If you were her friend at 8 and were in trouble in Mexico for massacring some nuns, she’d come down and help you because you were her friend. On the flip side, if she decides she doesn’t like you, she will hate you forever. Don’t try to intimidate Ronda. She had her sisters, and she’s like ‘Nobody’s ever going to pick on me again.’”

Rousey DeMars recalls Ronda returning from a run and practice one day, then going on a 25-mile bicycle ride, telling her mom at the end, “When I look across the mat at that other girl, I want to know that there’s no way she trained harder than me.”

Given her dominance, does Rousey feel unbeatable against Carmouche?

“If I thought I was unbeatable, I’d be sitting on my couch eating Ben & Jerry’s now,” she said. “I work hard because I know anything can happen. All I can do is train as hard as I can and make the chances of me winning as statistically great as possible.”

Rousey took a brief moment recently to reflect on her standing, leaving a voicemail for her mother summarizing their journey.

“Hey Mom, I know you were worried I’d be a waste of life when I was living in my car,” Rousey said. “Well, I just became president of my own corporation.”

Having known Rousey since age 14, Gamburyan has great admiration for his friend now headlining a UFC card.

“I never wanted her to fight. She’s a cute girl,” Gamburyan said. “I didn’t want her to hurt her nose. But her toughness is at a different level. I know MMA people are saying it’s not a girls’ sport, but her mentality, that toughness, that’s something everyone can appreciate.”