Pee-wee's Big Adventure

Pee-wee Herman is a puer aeternus with a heavily accessorized bicycle that he treasures and that his neighbor, Francis Buxton, covets. A bike shop employee, Dottie, has a crush on Pee-wee, but he does not reciprocate it. When Pee-wee's bike gets stolen while at the mall, he offers a $10,000 reward for its return. Francis, who had paid to have someone steal the bike, is frightened by Pee-wee's relentlessness and has it sent away. Desperate, Pee-wee visits a psychic, Madam Ruby, who claims that the bike is in the basement of the Alamo. Pee-wee hitchhikes to Texas, getting rides from a fugitive, Mickey, and from Large Marge (the ghost of a deceased truck driver).
At a truck stop, Pee-wee discovers his wallet is missing and pays for his meal by washing dishes. He befriends Simone, a waitress who dreams of visiting Paris. As they watch the sun rise at a dinosaur museum, Pee-wee encourages her to follow her dreams, only to be chased by her jealous boyfriend, Andy. Pee-Wee escapes onto a moving train where he meets a hobo named Jack. He gets off at San Antonio and immediately heads over to the Alamo, only to find the building has no basement. After calling Dottie and asking her to wire him some money, he is attacked by Andy again. Pee-wee evades Andy at a rodeo by disguising himself as a bull rider. Forced to ride for real, Pee-wee does surprisingly well but receives a concussion.
Pee-wee enters a biker bar to make a phone call, but an outlaw motorcycle club called "Satan's Helpers" tell Pee-wee that the bar is not open to the public and kick Pee-wee out. Pee-wee accidentally knocks over their bikes, but escapes certain death by dancing to the song "Tequila". The bikers have a change in heart and decide to give Pee-wee a motorcycle to get home, but gets into an accident outside the bar and ends up in the hospital. Awakening, Pee-Wee sees a news report that Warner Bros. Studios has acquired his bike where it is being used as a movie prop for a pretentious child actor named Kevin Morton. The scene quickly jumps from Texas to Hollywood, where Pee-wee gains access to the WB studio by pretending to be with Milton Berle's entourage. By disguising himself as an extra on Kevin Morton's movie set, Pee-wee recaptures his bike. However, he must soon evade multiple security guards and wreaks havoc across multiple stages.
Outside, Pee-wee discovers a burning pet shop. He heroically rescues the animals, but faints on the sidewalk with a hand full of snakes just as first responders arrive. Although the firemen call Pee-wee a hero, the police arrest him. Warner Brothers executive Terry Hawthorne has the charges against Pee-wee dismissed in exchange for making the adventure of retrieving his bike into a movie.
Later at a drive-in theater, Pee-wee and Dottie attend the movie premiere of his supposed biopic, an action B-movie starring James Brolin as "P.W. Herman" (who introduces himself as "Herman, P.W. Herman") and Morgan Fairchild as Dottie. After ninjas attack the couple and steal an important sport bike called the X-1, P.W. gets a phone call from the unseen President of the United States, who explains that the X-1 has an important microfilm concealed in it, which the Soviets must not be allowed to discover. Pee-wee has a cameo appearance as a hotel bellhop. At the premiere, Pee-wee gives refreshments to all the people he met along his journey including Mickey, Simone, and Jack. Pee-wee also encounters Francis, who brags to the media about how knowledgeable he is about Pee-wee's bike, but makes a fool of himself using one of the bicycle's gadgets. Pee-wee then offers to go bicycling with Dottie, who wonders why he is not staying for the rest of the film, causing Pee-wee to remark that it is not necessary for him to see the movie, since he lived it.

Question: What roll did Josh Brolin play in Pee Wee Herman's biopic?
Answer: P.W. Herman