The 80s saw the success of many great horror characters, many that went on to have many movies made about them. Other great horror characters may have had movies done about them in the 60s and 70s but sequels didn’t come until the 80s or later.
The 80s saw the emergence of:
Annie Wilkes (Misery)
Chucky (Child’s Play)
Dr Herbert West (The Reanimator)
(A Nightmare on Elm Street)
Jason Vorhees (Friday the 13th)
First one was in late 70s but all the sequels came in the 80s.
Pennywise the Clown
(The Puppet Master)
The Toxic Avenger
Other earlier horror characters that had sequels made about them in the 80s:
Leatherface (Texas Chainsaw Massacre)
Norman Bates (Psycho)