Tales to Astonish #46 Aug 1963
"...When Cyclops Walks the Earth"
With a lull in crime, Henry Pym and Janet Van Dyne decide to take a vacation. Traveling to Greece,
they hear stories of a giant monster that has been reported to be stealing ships from sea,
which makes them unable to get someone to take them to the island. However, one man later lends them one.

Renting a boat and assuming their guises of Ant-Man and the Wasp, the two heroes seek to solve the mystery of this apparent sea monster.

While out at sea, they are attacked by what appears to be a Cyclops of Greek myth.
Shrinking down to ant-size so as not to be noticed by the giant creature, the heroes allow the monster to capture their boat.
The monster brings them to an island where they find all the missing people are being held captive by the monster Cyclops.

While exploring the island, they discover that aliens are plotting to take over the Earth (believe it or not),
and that they've captured the fishermen and sailors in order to study them.
They also learn that the cyclops is actually a robot the aliens created to capture their specimens.
The aliens, known as A-Chiltarians, surmise that the Human race is inferior to themselves and, thus easy prey for global conquest.
The invaders order the Cyclops to destroy the Humans on the island.

Ant-Man sends the Wasp to free the sailors while he tries to find a way to stop the Cyclops.

Entering into its mechanisms through the robot's mouth, Ant-Man realises that he can control the Cyclops by adjusting the frequency of his helmet.
He then uses the Cyclops to free the sailors, and scare away the aliens, leaving them to believe that Humans are more powerful than they had originally posited.

With the aliens defeated, and the sailors free, Ant-Man commands the Cyclops to walk to the bottom of the ocean to be lost at sea forever.
Ant-Man and Wasp return to the mainland where they enjoy their vacation for a few days before returning home.

Script by Stan Lee and Ernie Hart [as H. E. Huntley], art by Don Heck