There are tonnes of plans for comic books out there that never came to fruition, but this certainly stands as one of the strangest to come to light - an official adaptation of Final Fantasy IV (first released as Final Fantasy II in the US) from Kurt Busiek, Del Barras and Mike Mignola.
Planned for release in late 1992, the Final Fantasy comic originally came about as Squaresoft offered Busiek the chance to write an original story set in the world of the first Final Fantasy game - before the company, pleased with his initial outline, then decided to let him adapt the story of FFIV to tie-in with the games' western release. 4 issues were planned, and Busiek wrote the script for all of them, with art by renowned comics artist Del Barras and covers by Mike Mignola. Unfortunately the series never happened because Disney's Hollywood Comic, who were going to publish the series, went bust in 1993 - that is, until it was brought to light by Thaddeus Boyd a few years ago. A recent tumblr post reblogged by Busiek himself got Boyd to dig out a few of the original planned covers by Mignola:
What's most interesting about this find is how it would've brought together some of prominent Comic creators before they were truly famous - at the time, Busiek had yet to be shot to fame for his work creating Marvels, and two years later Mignola would go on to draw Hellboy. It's fascinating to see the two come together in the early days of their careers on such an obscure project like this. [Corporate Sellout via Robot 6]