Michael Myers began his existence in the Halloween series as The Shape. His history goes through a few revisions throughout each film - starting as an existential threat made real through violence, then a supernatural monster and potential savior, to the product of a world that values flesh as just another possession.
Appears in: All the Halloween films except Halloween III: Season of the Witch Laurie appears in many of the films with different last names. Starting with the second film on she is identified as the sister of Michael Myers, though she doesn't always know it, but is constantly the target of his murderous eye.
Appears in: Halloween (1978), Halloween II (1981), H20, and Resurrection with Jamie Lee Curtis - Halloween (2007) and Halloween II (2009) with Scout Taylor-Compton.Dr. Loomis is another one of the key figures of Halloween as the psychiatrist who tries to treat Michael Myers. He's played with airs ranging from ominous to pompous and seems to have inherited some of Michael's indestructible flesh during his treatment.
Appears in: Halloween (1978), Halloween II (1981), Halloween 4 through 6 with Donald Pleasence - Halloween (2007) and Halloween II (2009) with Malcolm McDowellJamie Lloyd, in the alternate universe Halloween timeline followed by films 4 through 6, is the daughter of Laurie who becomes the target of Michael after a car accident kills Laurie. In the sixth film she is in the film very briefly to give birth to the next Myers generation.
Appears in: Halloween 4 through 6, actress Danielle Harris has a supporting role as Annie, friend to Laurie, in Rob Zombie's Halloween (2007) and Halloween II (2009).Dr. Challis (Tom Atkins) is the main character of Halloween III: Season of the Witch and his involvement with the franchise, but hopefully not that beautiful mustache, ends there.
Appears in: Halloween III: Season of the Witch
Behind the scenes
John Carpenter is the director of the first Halloween film, co-writing the script with Debra Hill. His involvement with the series waned to the point where his creative input involved walking to the set, offering a greeting, and walking off.
Debra Hill co-wrote the first Halloween movie along with John Carpenter and produced many other installments. She passed away in 2005.Moustapha Akkad produced every single movie in the Halloween franchise until his murder in 2005. His son, Malek, continued producing the films afterward.
Rob Zombie - animator, rocker, horror enthusiast - rebooted the franchise in 2007 to a wide audience, followed by directing a divisive sequel in 2009. I've been on both sides of the love / hate spectrum, but have come to embrace his passion for horror both cerebral and visceral.