Synopsis for
Attack of the Giant Leeches (1959)

While poaching in the Florida Everglades, Lem Sawyer [George Cisar] fires five shots into a giant leechlike creature, but none of the old boys lolling around in Dave Walker's [Bruno VeSota] General Store will buy that it was anything other than one too many swigs on Lem's jug of moonshine. Besides, there is Dave's slutty she-cat of a wife, Liz [Yvette Vickers], running around in various shades of undress to occupy their conversation. However, when State Game Warden Steve Benton [Ken Clark] comes upon Lem's body, his face covered with marks like those that would be made by the tentacles of a giant squid or octopus, it's apparent that something unnatural killed Lem, and it wasn't an overgrown gater, as Sheriff Kovis [Gene Roth] would have Steve believe. For the next two days, Steve takes his girlfriend, Nan Greyson [Jan Shepard], and a rowboat, and they go searching the back channels of the swamp, but to no avail.

Meanwhile, Dave and Liz Walker are having another of their fights. Liz abhors her fat, balding, wimp of a husband. When Dave leaves the store to make a grocery delivery, Liz sneaks out with her current paramour, Dave's best friend Cal Moulton [Michael Emmet]. Liz and Cal end up out in the swamps where they are found in each others' arms by Liz's husband and his double-barreled shotgun. In order to teach them a lesson, Dave chases Liz and Cal through the swamp, firing rounds of shot over their heads until they finally come to a stalemate along the riverbank. Still as mad as a hornet, Dave forces Liz and Cal into the water. When Dave thinks that they've had enough, he tells them to come out of the water, but it's too late. Two giant leeches sneak up behind Liz and Cal and carry them off. When Dave tries to explain to Sheriff Kovis about the creatures, Kovis concludes that Dave shot them both and hid their bodies in the swamp. The next day, they search the swamps but find no bodies, so the sheriff arrests Dave for murder. Later that day, Dave hangs himself in his cell.

Nan's father, Doc Greyson [Tyler McVey], suggests that they plant explosives in the swamp in order to bring up the bodies, but Steve refuses on grounds that it would kill all the wildlife in the area and wreck what took nature years to build up. Funny thing is, there is no wildlife. Two old poachers, Sam Peters [?] and Slim Reed [Dan White], both after the $50 finder's fee should they locate the bodies, have gone poking around in the reeds, figuring that gaters have planted the bodies there in order to ripen them for a few days, but they've noticed that even the gaters have disappeared from a part of the swamp that should be crawling with them. Just as they conclude that there really is something suspicious in the swamp and it would be best to get on dry land, the giant leeches overturn their boat and carry their bodies to a cave with an underwater air pocket where they have also taken Liz and Cal so that they can feed at will on their blood.

When Steve hears that Sam and Reed have also disappeared, he rounds up a search party and some bloodhounds, and they go searching the swamps again -- but find nothing. The next day, Doc Greyson decides to take things into his own hands. He plants dynamite in the middle of the swamp and sets it off. The blast dislodges the bodies of Cal Moulton, Sam Peters, and Slim Reed. The odd thing is that, although they've been missing for several days and every drop of blood has been drained from their bodies, death only set in a few hours ago. Doc Greyson concludes that the creatures are holding the bodies in some underwater caves, and Liz Walker might still be down there...alive.

Steve sends for his friend Mike, who brings along some SCUBA gear. While Mike waits in the boat, Steve takes a speargun and goes looking for underwater caves. Not long after going down, he encounters one of the leeches and shoots it. Liz Walker's body dislodges and floats to the surface. After re-arming himself with another speargun, Steve goes back down to make sure the leech is dead. It's not, so Mike dives in, and together they overpower the creature. Unfortunately, where there is one giant leech, there's probably more, so Steve agrees that the best policy is to dynamite the swamp. They plant charges, blast away, and the bodies of several giant leeches come floating to the surface. As they walk away from the water, the peculiar gurgling sound of another giant leech can be heard among the reeds. [Original Synopsis by bj_kuehl.]