Talk Show Hoaxer Pranked NFL, NBA Coaches Tonight the man you might have seen on tv before, perhaps you were riveted by his story, the problem is, each time he appeared, it was a different story. Fooling tv hosts and producers and so many of you at home. Is he a comic? Or a criminal? You decide, here's abc's nick watt. Reporter: Kenny tarr is a rather unusual tv star. Here you're watching "ken," a gypsy king with an eye for the ladies on "the bill cunningham show." I'm of hungiar and magadarian decent. That means the man can go gallivanting with another woman as long as he is direct and tells her the truth. Reporter: And this is "eddie" on "the trisha goddard show" where he told the world he's a trucker with a gambling habit and a penchant for prostitutes. Do you have sex in your truck? I've had sex in my truck before, yes. These hosts are just, just completely, uh, buying everything you're saying. Reporter: On "judge alex," "kenneth kenyon tarr" was a plumber, with an unusual complaint. I was locked in a mortuary for 14 hours. You were locked in. Okay, now I have to hear this. Reporter: So will the real kenny tarr please stand up? Truth is, this clown is a 32-year-old college drop-out. He lives in this modest apartment in hollywood. He's single. Hi, how are you doing today? I was looking to speak to someone in the literary department, please. Reporter: He's an unsuccessful writer and stand-up comedian. Do you guys actually work for a living? I wish I -- I don't know. Reporter: Lying, hoaxing, fooling. This, says kenny tarr, is his art. Andy kaufman, andy warhol, great, I'm glad they existed, but they're nothing compared to me. I don't really even look at them like peers. Reporter: What? I don't have any respect -- Reporter: What! What! What! -- For their accomplishments. Reporter: You are saying that your performances are superior to andy kaufman? Completely! I'm not being bragadoccious, I'm being real. Reporter: We hung out with tarr back in september, before he found some genuine fame by getting arrested. More on that a little later. This is ed. He invited us behind the scenes for this exclusive glimpse of his process -- spinning yarn after yarn for reality show producers. I'm a jazz musician I travel about 48 weeks a year. Reporter: Tarr does it, he says, for the creative thrill. Do you enjoy it, do you get a rush, is there adrenaline? I feel like, um, just like robert DeNiro or just like any other actor feels. I just got back from somalia. How are you? I feel creatively satisfied. Reporter: How does he get on these shows? The producers of unfaithful believed he was a security expert caught in a baseless relationship. I couldn't believe how easy it was to have an affair. How could he convince the producers he was that plumber. I usually have to fabricate some document. I give a form. I'm a plumber, sewage blah, blah, blah. Reporter: Judge alex just found out he was fake. He had me totally convinced. Reporter: Judge alex tapes nine or ten shows a day when they are in production. We have been burned a couple times from cases we thought were real and turned out to be fake. I taped almost 1400 cases. So that's not a bad ratio Reporter: Tarr says his success rate is about one tv appearance for every 12 crazy pitches. My computer was damaged and i sued my fiancee, and then, uh, we went to france, and she left me at the altar in marseilles. Reporter: His first tv hoax was back in 1997 on a show called "forgive or forget." Tarr claimed he'd stolen his brother's fiancee. Has a producer ever busted you? No, no, no. They were always like, "this guy is so over the top, this guy is so good for tv, this guy has such an interesting story. we got burned!" Some of them pay an appearance fee, maybe a hundred bucks. They all pay for flights hotels and food. I always tell them I have a job that pays me and they need to reimburse me for wages that don't exist. Reporter: That's fraudulent! Is it? I don't know words like that. Reporter: And on the court shows, there's a pay-out. Tarr's career earnings? Maybe $20,000. So he's not really doing this for the money. We asked an expert, who refers to people like tarr as serial hoaxers, why do they do it? This is an individual who may see these other folks being much more successful than he is, who are much richer, but in his mind they really don't deserve it. Reporter: Have you ever had a psychiatric evaluation? Oh, absolutely not. I keep myself out of the whole world of, like, people knowing who I am. Reporter: Are you actually kenny tarr or is this a fabrication? You're looking at kenny tarr right now. Reporter: But, back in september, tarr told us it was getting harder to hoax tv shows. Do you think every talk show producer now has a photo of you above their desk? They should. Hi! Reporter: So tarr hit the phones. Again, he says this time he targeted about three dozen basketball and football coaches. I'm the best prank caller that ever existed. Reporter: Here he is apparently talking to san diego chargers offensive coordinator, ken whisenhunt. And what kind of position are you talking about? Reporter: Tarr is pretending to be with the university of texas. And he's offering whisenhunt the head coach job. He posted this video online. I'll make it very clear that you're the one that I would like to select, and we'll go from there. That sounds good. Reporter: He may think it was a harmless prank, but in california, you can't record a conversation without the other person's consent. Mr. Tarr was booked for 632a of the penal code, which is felony eavesdropping. Reporter: This week, tarr wound up in an l.A. Court room as kenneth edward tarr, for real, no joke, with a new suit and a tidy haircut, facing potentially three years in the clink. Yes, indeed! Reporter: Tarr admits he made the calls. But pled not guilty. His lawyer, who calls tarr a modern day mark twain, says this is a malicious prosecution. At the behest of the nfl because the nfl has hurt feelings they have filed felony charges on this prankster. Reporter: Who later tweeted, "it is all a hoax within a hoax and I'll tell you when it is not. There's no one else that's ever gotten close to what I've done. I think that there's oscars to be won. I think that there's other things to be done. Reporter: Will infamy and arrest and this "20/20" tell-all mean this is the last we'll see of kenny tarr? Reporter: I'm guessing he'll be back. Watch out. &#9834;