Published Mar 1970 by Marvel.
"The Monster from the Lost Lagoon!" Script by Stan Lee. Pencils by Jack Kirby. Inks by Frank Giacoia. Cover by Jack Kirby and John Verpoorten. At the request of the U.S. Navy, the Fantastic Four investigate mysterious disappearances of ships off the Florida coast! A local legend says that a sea creature patrols the waters wreaking havoc! Could that be true? With help from a skilled aquarium worker, Reed, Ben, and Johnny explore the deep waters of the lagoon! But near the floor of the lagoon, the aquarium worker turns traitor! And then turns into the Monster from the Lost Lagoon! What a revoltin' development! After Mister Fantastic and the Human Torch succumb to the crushing water pressure, the ever-lovin' Thing tackles the monster one-on-one! Can Ben Grimm maneuver past the monster and solve the mystery of the lost lagoon? Cameo appearance by Franklin. (Notes: The Monster from the Lost Lagoon encounters the FF again in Fantastic Four 124. The letters page contains a statement of ownership: average print run 546,820; average paid circulation 340,363.) 32 pages Cover price $0.15.