Often a film becomes successful, popular or attains cult status and the franchise produces spin-offs that may include comics.
In particular, the Aliens and Predator comics have crossed over with The Terminator, Superman, Batman, Judge Dredd and Green Lantern.
There are a number of companies that specialise in licensed properties, including Dark Horse, Titan, Avatar and Dynamite Entertainment.
With the bigger series the license can often pass between a number of companies over the history of the title.
Crossover of two intellectual properties from 20th Century Studios, later adapted into two feature films in 2004 and 2007 respectively.