Mister Mann Frisby, who has written for the Inquirer and Daily News, said he pitched the concept to his former friend 10 years ago.
Scott was enthusiastic about the idea and promised to split the gross revenues "50-50" with Frisby if he could nail down a deal, according to the lawsuit filed Thursday in Philadelphia Common Pleas Court.
Frisby said it was his job to choose appropriate lyrics and prepare marketing and promotional materials.
As Scott's fame began to rocket, she "unilaterally put Frisby's activities 'on hold' " while she pursued her acting projects, the lawsuit alleges. The suit was first reported by CourthouseNews.com.
In January 2017, Scott announced she was launching her own Hallmark Mahogany greeting-card line featuring lyrics from 20 of her songs.
Hallmark had approached her about partnering with the company five years prior, she said, "but it wasn't until last year both parties met and she displayed her idea," the Associated Press wrote.
In August, eight months after the launch, Frisby discovered Scott "had concealed her actions" and had proceeded without him, his lawsuit says.
Frisby says Scott breached her oral agreement with him by "falsely stating" she was putting the deal on hold, circumventing him, and securing the Hallmark deal without telling him.
Neither Scott nor Frisby could be immediately reached for comment Saturday.
Frisby, who became a novelist and motivational speaker after leaving the Daily News, is demanding 50 percent of Scott's greeting-card profits and more than $50,000 in damages.