The Stuff (1985)

Wikipedia wrote:A couple of railroad workers discover a yogurt-like white substance bubbling out of the ground. It's found to be sweet and addictive. Later, the substance is marketed as The Stuff and it's being sold to the general public in pint containers (incorrectly labeled ".474mL") like ice cream. It is marketed as having no calories and as being sweet, creamy, and filling. The Stuff quickly becomes a nationwide craze and drastically hurts the sales of ice cream.

Wikipedia wrote:Former FBI agent turned industrial saboteur David "Mo" Rutherford is hired by the leaders of the suffering ice cream industry, as well as junk food mogul Charles W. "Chocolate Chip Charlie" Hobbs, to find out exactly what The Stuff is and destroy it. His efforts reveal that the craze for the dessert is far deadlier and much more evil than anyone had believed – The Stuff is actually a living, parasitic, and possibly sentient organism and it gradually takes over the brain, mutating those who eat it into bizarre zombie-like creatures, before consuming them from the inside and leaving them empty shells of their former selves.

Wikipedia wrote:Brooke Adams, Laurene Landon, Tammy Grimes, Abe Vigoda, and Clara Peller as Stuff commercial guest stars; Eric Bogosian (uncredited) as Supermarket clerk; Patrick Dempsey (uncredited) as Underground stuff buyer #2; Mira Sorvino (uncredited) as Factory worker; she had come to visit her father, Paul Sorvino, on set, and was used as an extra. Cohen wanted to cast Arsenio Hall as Chocolate Chip Charlie W. Hobbs, since he thought he was not only good actor, but also a rising star. However, the executives at New World Pictures wanted someone more recognizable, and thus cast Garrett Morris instead