In my copy of Leonard Maltin's Movie Guide I learned about a horror movie named Abby and it debuted in the 70's. It starred actress Carol Speed as Abby and was a variation of The Exorcist but Abby has never been seen on TV or released on DVD or video for years because people thought it was a ripoff of The Exorcist. Have you ever heard of this horror movie before?
Bestie

Yes, I've seen it. It's fun cheesy blaxploitation, definitely a ripoff of The Exorcist, it was originally going to be called The Blaxorcist.

Warner Bros sued American International who owned Abby for being a rip off of their film The Exorcist. Though Abby was no where as blatant a rip off as some non-American films like the Turkish Seytan (1974) aka Turkish Exorcist

William Marshall who played Blackula was in it, along with Austin Stoker (Assault On Precinct 13)

Yeah, sadly both the DVD and Blu Ray released are out of print.