He's got the aerodynamics of a pot roast, but on Thursday, Tillman the English bulldog will show the nation how he can whip around the pavement on his skateboard as nimbly as any kid.

"We need to figure out how to hook up some wind power to Tillman as he passes by," said Tillman's human, Ron Davis, 39, of Silver Strand.

Davis and his talented canine will appear with 11 other dogs and their owners from around the nation on a CBS reality show called the "Greatest American Dog." The 10-episode series, which debuts Thursday at 8 p.m., will feature the 12 dogs and their owners as they participate in various competitions designed to test what the judges consider to be the characteristics of the greatest American dog: "courage, loyalty, intelligence, personality, agility and coordination," show producer R.J. Cutler said.

Colleen Sullivan, vice president of publicity for CBS, said the contestants were chosen from a combination of auditions and research.

"Our casting department chose from thousands of dogs," Sullivan said. "We also actively went to dog-specific (Web) sites."

Sullivan said casting directors weren't looking for Westminster Dog Show dogs, but rather pooches and owners with personality and potential. The dogs they chose ranged from pageant dogs to pets like Tillman, who were trained at home.

"The biggest criterion wasn't who knew the most tricks or who had the most professional experience," Sullivan said.

Davis said casting directors contacted him in March after seeing Tillman on the Internet.

"At first I was like, Ahhhhh no,'" Davis said. "The whole reality thing — they can make you look like an idiot or a jerk, or they can make you look like a saint. It's all in the editing."

But Davis finally agreed to do it. One day before CBS contacted him, the construction manager had been laid off from his job due to the housing slowdown. As the married father of an 8-year-old boy, Davis had to consider his family, and the $250,000 prize that he and Tillman would be competing for.

"When you don't have a job, a quarter of a million dollars is a lot of money," Davis said. "When you have a job, a quarter of a million dollars is a lot of money."

The taping

Tillman, Davis and the other dogs and owners stayed together in an Agoura Hills estate for the six weeks while the show was taped. The producers renamed the mansion "Canine Academy" for the duration.

Tillman is more of a pavement dog, so the grass surrounding the estate was a new experience for him, Davis said.

"For Tillman to see grass was a treat," Davis said. "He just kind of stared at it. Then he went to random places to poo and pee at will."

The show already has been taped, so Davis and Tillman know the outcome, but Davis is under contractual obligation not to reveal it.

And Tillman doesn't seem to care.

"His goal in life is, Where's my skateboard,'" Davis said.

The show consists of daily competitions with weekly eliminations determined by three judges: Wendy Diamond, editor in chief of Animal Fair Magazine; Allan Reznik, editor at large of Dog World and Dog Fancy magazines; and Victoria Stilwell, hot off the TV series "It's Me or the Dog."

The show will be hosted by zoologist/television personality Jarod Miller.

Davis can't speak about the show too much, but he did say there were definite people dynamics and definite doggy dynamics.

"There was one of everybody this wonderful nation of ours has to offer," Davis said. "Having people away from their families some people can handle that; some people cannot handle that."

During the taping, Davis said he did miss his wife of 10 years, Erika, and their son, Reef. Tillman slept with Ron every night in a snoring lump at the foot of the bed — just like he always does — and he had his skateboard, so his world was more intact.

Life after reality TV

As they wait for the show's premiere, Tillman and Davis continue to skateboard almost every day and do some skimboarding, which Tillman took up last summer.

"Last summer, when the heat wave hit, I got a little worried for Tillman to skateboard," Davis said.

To make sure that his dog didn't get overheated, Davis bought him a skimboard, took him out to the beach near their home and, in just a short time, Tillman figured out that this was just like skateboarding, only with splashing.

Davis is trying to teach Tillman to surf, too. But he tends to sink like a rock, so Davis has purchased a life jacket for him.

"He's built like a wide receiver for the NFL," Davis said.

Davis said he has no idea how he and Tillman will come off on the show because he hasn't seen the finished product, but he'll be watching the reality show with interest.

"People ask me, Would you do it again?'" Davis said. "I tell them, Ask me again in six months.'"