The prolific author says the Mouse House hasn’t paid him a penny for his novelizations of the iconic franchise since its 2012 purchase of Lucasfilm, the studio that birthed Luke Skywalker and Darth Vader.

In an open letter addressed to “Mickey,” Foster said he’s owed royalties for his 1976 book version of the first “Star Wars” film, which he ghost-wrote for series creator George Lucas, and the 1978 sequel “Splinter of the Mind’s Eye.” He’s also missing fees for his trio of novels based on the hit “Alien” films, which became Disney’s after it acquired 20th Century Fox last year, he said.

“When one company buys another, they acquire its liabilities as well as its assets. You’re certainly reaping the benefits of the assets,” Foster, 74, wrote in the letter released this week by the Science Fiction & Fantasy Writers of America. “I’d very much like my miniscule (though it’s not small to me) share.”

Foster added that Disney has ignored his agents’ and legal reps’ efforts to collect the cash and pressed him to sign a non-disclosure agreement before even starting negotiations — something no one else has ever asked him to do.

Foster said he could use the money as he battles “an advanced form of cancer” with which he was diagnosed in 2016. His wife is also grappling with “serious medical issues,” he said.

“I know this is what gargantuan corporations often do. Ignore requests and inquiries hoping the petitioner will simply go away. Or possibly die,” Foster wrote. “But I’m still here, and I am still entitled to what you owe me.”

Other authors and “Star Wars” fans rallied behind Foster on Twitter, with some noting that he helped the franchise become the beloved cash cow it is today. Disney raked in more than $4.4 billion at the global box office from the three latest “Star Wars” sequels, and the spinoff TV series “The Mandalorian” helped draw viewers to its Disney+ streaming service.

Disney did not immediately respond to a request for comment Friday. But the Mouse House told The Verge that it has been in talks with Foster for more than a year about the “Alien” books and hadn’t previously heard any complaints about the “Star Wars” titles. The company also reportedly claimed non-disclosure agreements are standard for such negotiations.

Mary Robinette Kowal, president of the Science Fiction & Fantasy Writers of America, said it was “unprecedented” for the group to speak out publicly about a writer’s dispute with a publisher — especially one as large as Disney.

“They believe they have the right to publish work, but are not obligated to pay the writer no matter what the contract says,” Kowal said in a statement. “If we let this stand, it could set precedent to fundamentally alter the way copyright and contracts operate in the United States.”