Fantastic Four #45 (December, 1965).
Eternals and Deviants
Earth Eternals and Deviants
"Mercury" (Makkari), "Minerva" (Thena), "Vulcan" (Valkin), "Jupiter" (Zuras), "Pluto" (Kro) , "William Carmody"/Eternal Brain all appeared within the "Mercury" and "Eternal Brain" stories in Red Raven #1 (August, 1940).
Uranian Eternals first appeared in Marvel Boy #1 (December, 1950).
Deviants and Earth Eternals (Polar and Olympians) first appeared presented as such in Eternals #1 (July, 1976).
Giganto appearing in Fantastic Four #1 (November, 1961).
The Deviant Skrulls (commonly known as Skrulls) were first introduced in Fantastic Four #2 (January, 1962) although Zankor appeared in Marvel: The Lost Generation #11, retconned into a Skrull only in Amazing Adult Fantasy #7 (April, 2000)
They were retconned as the deviant branch of their race in Silver Surfer Annual #1 (August, 1988).
The Xartan Deviants (commonly known as Xartans) were introduced in Journey into Mystery #90 (March, 1963), but were only stated as Deviants in Official Handbook of the Marvel Universe #12 (December, 1983)