1965's "The Navy vs. the Night Monsters" served as cofeature for Realart's already completed "Women of the Prehistoric Planet," both produced by George Edwards and an uncredited Roger Corman, this title written and directed by Michael A. Hoey, son of character actor Dennis Hoey. An adaptation of Murray Leinster's 1959 novel "The Monster from Earth's End" had been in limbo for a number of years (working titles "The Nightcrawlers" and "Monsters of the Night"), Hoey's script trying to recapture "The Thing From Another World" in its isolated setting and unseen terrors (actually more in tune with John Carpenter's 1982 remake). Animals and prehistoric vegetation found in Antarctica are on a flight to the US, making a refueling stop on Gow Island in the South Pacific when unforeseen occurrences leave the plane devoid of all personnel but the pilot, in a state of shock from which he never recovers. One penguin is noticeably missing but the remainder still on board, while the botanical marvels receive a proper burial in the tropical soil near the naval base commanded by Anthony Eisley's Lt. Charles Brown. A strange corrosive substance is found on the plane and even some of the buildings, before the discovery of the fist-sized creatures responsible, designed to look like large spiders. Walter Sande's Dr. Beecham examines one and believes that it's only an infant version of an adult, omnivorous trees based at the South Pole with the ability to pull up the roots and pursue its prey under frigid conditions, now growing and multiplying in the island humidity. Hoey's script is weak on characterization, clunky dialogue, and too much unfunny comic relief, but the mysteries increase nicely until the running time is used up, the payoff achieved by poorly integrated stock footage of fighter jets dropping napalm on the monsters, their scenes added in postproduction by actor/director Jon Hall. Hoey's disappointment in the bereft bark also required Arthur C. Pierce to shoot scenes of mainland authorities arriving at the final solution, just to bring the picture up to feature length. Eisley's assessment to maintain suspense by keeping the focus on the island turned out to be in accord with his director, and while it's not "The Day of the Triffids" it remains a better film than its camp reputation, much of it brought on by the wooden presence of an unglamorous Mamie Van Doren, who owed Corman one more picture on her contract, Anthony Eisley previously introduced in Corman's "The Wasp Woman" in 1959.