Made back in 1964 but not released until 1971. What obviously hurts this one so much in my mind is that it was paired up with the far superior and vastly gorier(and in color!) I DRINK YOUR BLOOD by producer/distributor Jerry Gross throughout the 70s. Taken on it's own it's not a terrible movie. Originally titled ZOMBIE, what you're dealing with here are those classic voodoo zombies(though the plot does explain that snake venom is somehow responsible for these bug-eyed shambling killers also). You get heads chopped off with machetes, a semi-mad scientist, fried egg zombies and lots of voodoo dancing. Directed by Del Tenney of HORROR OF PARTY BEACH fame, which along with this movie would make a way more suitable double feature. AKA CARIBBEAN ADVENTURE(what a dull title!)
There is a 2019 remake of this but as you might suspect it looks pretty dreadful!