Without him, directors like Lloyd Kaufman and John Waters would certainly have had different careers and perhaps now we would find them working inside a factory.
John Waters continually thanks him whenever he gets the chance (he even played a small part in Blood feast 2 as a homosexual priest).
We are talking about Herschell Gordon Lewis (Pittsburgh, June 15, 1929 - Fort Lauderdale, September 26, 2016) the so-called father of splatter.
The one who invented this sub-genre of horror in the 60s despite the meager means available, incompetent actors and directorial qualities inferior to his other colleagues.
If you really don't know who he is, there is the wikipedia page Herschell Gordon Lewis
There also many books dedicated to Lewis.
According to the imdb site Lewis has directed 38 films.

2017 Herschell Gordon Lewis' BloodMania
2009 The Uh Oh Show
2002 Blood Feast 2: All U Can Eat
1972 The Gore Gore Girls
1971 Black Love (as R.L. Smith)
1971 The Year of the Yahoo!
1971 This Stuff'll Kill Ya!
1970 The Wizard of Gore
1970 Miss Nymphet's Zap-In (as Sheldon Seymour)
1969 Linda and Abilene (as Mark Hansen)
1969 The Ecstasies of Women (as Mark Hansen)
1968 How to Make a Doll
1968 Just for the Hell of It
1968 The Alley Tramp (as Armand Parys)
1968 Suburban Roulette
1968 She-Devils on Wheels
1967 The Magic Land of Mother Goose
1967 Blast Off Girls
1967 The Girl, the Body, and the Pill
1967 The Gruesome Twosome
1967 A Taste of Blood
1967 Something Weird
1966 Jimmy, the Boy Wonder
1966 A Hot Night at the Go Go Lounge! (Short) (uncredited)
1965 Sin, Suffer and Repent (Documentary)
1965 Color Me Blood Red (as Herschell G. Lewis)
1965 Monster a-Go Go (uncredited)
1964 Moonshine Mountain
1964 2000 Maniacs
1963 Scum of the Earth (as Lewis H. Gordon)
1963 Bell, Bare and Beautiful (as Lewis H. Gordon)
1963 Goldilocks and the Three Bares (as Lewis H. Gordon)
1963 Blood Feast
1963 Boin-n-g (as Lewis H. Gordon)
1962 Nature's Playmates (as Lewis H. Gordon)
1962 Daughter of the Sun (as Lewis H. Gordon)
1961 The Adventures of Lucky Pierre (as Lewis H. Gordon)
1961 Living Venus

There are also various remakes of Lewis' films.
For example, there is an unofficial remake of Blood feast called Blood Diner (1987) directed by director Jackie Kong.
Compared to Lewis's film, here we are in the parts of the demented Troma-style splatter.

2005 instead is 2001 Maniacs directed by Tim Sullivan.
A kind of remake of 2000 maniacs with Robert Englund among the cast.

2001 Maniacs was even made a sequel in 2010: 2001 Maniacs – Field of Screams, also directed by Tim Sullivan

In 2007, The wizard of gore was released, a pseudo remake of Lewis' film directed by Jeremy Kasten.
A remake of Blood feast directed by Marcel Walz also seems to be in the works.
Making remakes with capable actors, digital film, budgets Lewis never dreamed of doesn't make much sense in my opinion.
But that's how cinema goes today.