Fantastic Four (1961) #18
First appearance of the Super-Skrull. "A Skrull Walks Among Us!" is written by Stan Lee with art by Jack Kirby and Dick Ayers. The warlike Imperial Skrulls have never forgotten their ignominious defeat at the hands of the Fantastic Four (as witnessed in issue #2) and have been busy plotting to avenge their honor. All of the Skrull Empire's intergalactic wealth and scientific know-how has been put to the task of creating a being that the FF can never defeat. A lone warrior is given all of the abilities of our heroes: Mr. Fantastic's stretching powers; the Human Torch's flame; the Invisible Girl's invisibility and the Thing's titanic strength. But what's more, this Super-Skrull has been given powers beyond those of the FF. A demonstration of the Super-Skrull's impressive might convinces the Skrull Emperor that there's no way this plan can fail!
Meanwhile, on Earth, the FF try to enjoy a leisurely day shopping in New York City's fine department stores. However, their celebrity inevitably causes a minor panic as fans and well-wishers mob the quartet of adventurers. When an emergency broadcast announces that a spaceship has landed in Times Square, it takes all of our heroes' powers and ingenuity just to escape their adoring public. The Super-Skrull having landed his ship in the middle of Manhattan declares the Earth as the property of the Skrull Empire and dares the FF to try to stop him. They do try and they fail miserably as the alien bests each one of them in turn. Mr. Fantastic orders the team into retreat but soon comes up with another strategy. If the Super-Skrull is getting his power from the Skrull homeworld, perhaps there's some way to block that signal. On a lonely island in the Atlantic, the FF try out Reed's theory and put Sue Richards' bravery to the test as well.