These films were based on cartoons that were loved by many. There were attempts at making a live-action adaptation of these cartoons. However, these films didn't come to surface and were permanently redlit.
“Masters of the Universe 2: Cyborg was a planned sequel to the 1987 Masters of the Universe film...Masters of the Universe 2: Cyborg
“TMNT: The Next Mutation was a planned sequel in the original Teenage Mutant Ninja Turtles film...TMNT: The Next Mutation
“Scooby-Doo 3 was a planned sequel to Scooby-Doo 2: Monsters Unleashed that was set to be the...Scooby-Doo 3
“The Smurfs 3 is a proposed third installment in the live-action Smurfs franchise. The...The Smurfs 3