"Attack of the Giant Leeches" is a product of it's time. Set in a Florida swampland near Cape Canaveral, people are disappearing and the the body is found, the victim is void of blood. A federal park ranger comes to town and straightens out the rednecks, one Yvette Vickers of "Attack of the 50 Foot Woman" fame.
The film does create some moody and creepy scenes, until the giant leeches show up. Made of canvas or plastic, the giant leeches such their blood with an orifice the size of a life preserver. Also, the suffers from momentum kill when the scientific explanations intrude upon the murder and rampage. "Attack of the Giant Leeches" has the potential to become a great remake.