Does the thought of anything creepy crawly give you the heebie jeebies? Worms, snakes, spiders -- but what about butterflies or puppies? Some people have such an extreme fear of animals that even the most docile ones can freeze them with fear.
"For some people, the anxiety is so extreme that they can feel that animal touching them, crawling on them," said psychologist Dr. Robin Zasio. "They can feel the hair, the legs. They can feel it in their mouth, their hair, and it's a very real experience to them."
As a way to confront and get over their fears, patients come face-to-face with the critter or creature that haunted their every waking hour on Animal Planet's reality series, "My Extreme Animal Phobia," which airs on Fridays at 10 p.m. ET. The cure is a technique known as exposure therapy.
Watch the full story on "Nightline" tonight at 11:35 p.m. ET
Zasio, the founder of the Anxiety Treatment Center in Sacramento, Calif., is the star of the show and leads the therapy sessions. Her prescription is a lot of courage and a little bit of tough love.
"While talk therapy is important and helping people ... get at the root problem of their fears, ultimately to overcome anxiety, you have to face it," she said.
Each episode follows three people on a five-day journey of intense therapy -- where no one can hide from what scares them the most -- as a way to conquer their phobia. For 47-year-old Marvin Cruz, that phobia was pit bulls.
Cruz's treatment began quietly enough with pictures and video of the dog breed, but each level of exposure become stronger than the last and eventually Cruz was forced to come face-to-face with a pit bull at a park. But even just the sight of a pit bull puppy on a leash made Cruz, who is a mountain of man with piercings and face tattoos, break down and sob.
"I'm a coward," he said, as Zasio tried to console him.
The video of that scene from the show went viral on YouTube, and it struck many viewers as absurd, even hilarious, but for Cruz, the fear was real.
"A lot of [the online comments] were just insulting, 'how could this big guy cry over a little puppy,' but they didn't know what I went through," he said.
On the show, Cruz revealed he was 5 years old when he witnessed something that would haunt him for the rest of his life.
"My neighbor from like two doors down came over," he explained. "We were playing in the yard playing ball. This pit bull came in the backyard. It was growling like crazy. It attacked my neighbor, arms, legs, back, chest, I mean everywhere. He had over 1,000 stitches on his body. Ever since then, if I see a pit bull. I'm ice cold. I'm frozen."
Since then, Cruz wasn't just afraid to go near pit bulls, he was afraid to go outside and be out in the open. Only recently did he summon up the courage to go on a family walk but rode on an ATV so he could make a quick getaway in case a pit bull was lurking.
"I felt I could outrun them," Cruz said. "I had a bat in the side of the ATV, I kept that, a hammer and a bat."
What convinced Cruz to finally seek help for his phobia of pit bulls were his two daughters. Before therapy, he was too afraid to spend time with them outside.
"It destroys me," he said, tearing up. "I still, it still bothers me. I can only make up for so much lost time."
Marvin Cruz Slowly Comes to Terms With His Fear of Pit Bulls
After confronting the pit bull puppy at a park, Cruz slowly realized that what he was experiencing was not fear but guilt about what happened when he was a little boy.
"He was able to see that he was not so angry at pit bulls as he was angry at himself for not closing that gate and not taking responsibility for the harm that came to his friend," Zasio explained.
For Cruz, his final exposure was to climb inside a cage with two fully-grown pit bulls, where he was finally able to see the dogs' behavior as playful instead of threatening.
"I felt like a real man, seriously," Cruz said. "I felt like a real man, a real husband, a real father."
Cruz said he believes he never would have gotten over his fear if it hadn't been for exposure therapy and that the best way to conquer fears of anything, including animal phobias, is to face them head on.
"You have to go to the extreme, and I went to the extreme," Cruz said. "Trust me. Full extreme."
Perhaps his case proves that there is no extreme animal phobia that can't be tamed.
"The bottom line is that fear is not about reality, it's about doubt," Zasio said. "I need patients to sit with that doubt and test their fear."