This 13-page Kirby/Ayers story is reprinted from 1961's JOURNEY INTO MYSTERY #67. For the reprint, Gruto is recoloured from red to green (though oddly not on the cover, which takes the monster image from the Ditko original cover and redraws the human figures completely).
In this story, a reporter needs to come up with a big story to save his job. As fate would have it, he and his girlfriend happen across the crash landing of an alien ship containing Gruto.
Gruto has lost his memory, and the reporter decides to take advantage of that to pretend Gruto is the harbinger of an alien invasion, in order to make the story bigger. His lies eventually lead Gruto to be attacked and flee, when he finally regains his memory it turns out he was from an enlightened race send to share their secrets with Earth, but now he deems humans unworthy. The reporter loses everything, including his girlfriend.
Fun story with a nice turnaround on the conventions, and of course the usual great Kirby/Ayers artwork. Some odd captions in the narration, like this one from when the reporter is called into his editor's office: "Thirty-five fearful steps later I reached the door of doom". Very unlike most of the stories, I wonder if this was written by someone other than one of the regulars (I like Lieber scripted most of the Kirby stories of this era).
This story also has one of those "world balloons", for fans of those.