Guess a Classic Horror/Sci-Fi by a Description

[Mike Scott]

A teenager saves locals from a carnivorous menace.

THE GIANT GILA MONSTER

[Lunkenstein]

Dang! I gotta make mine harder. Your turn Mike.

[Mike Scott]

A tee . . er, young man saves his girlfriend from a decapitating monster.

[Memphremagog]

Monster Of Piedras Blancas

[Mike Scott]

Monster Of Piedras Blancas

Also starring Don Sullivan! 

[Memphremagog]

A guy gets frequent headaches, ends up taking the wrong medicine for them and winds up with a really disgusting habit..

[Anton Phibes]

A guy gets frequent headaches, ends up taking the wrong medicine for them and winds up with a really disgusting habit..

The Vampire 1957

[Memphremagog]

The Vampire 1957

Yes! Your turn!

[Anton Phibes]

A young lad is disowned by his family because of some extremely poor life decisions.... at a very early age.  After 15 years away from home, he returns in an attempt to re-unite with his only remaining family.  This is frowned upon by the locals.

[Lunkenstein]

HALLOWEEN (1978) ?

[Anton Phibes]

Ya got it. Your turn.

[Lunkenstein]

A scientist tricks a poor guy into becoming his latest experiment. Soon, murders abound and police search frantically for the fiend.

[Memphremagog]

I Was A Teenage Werewolf

[Lunkenstein]

Not that one.

[Lunkenstein]

IMDB has 2 different release years, depending on country. Could be late '50s or early '60s.