The blue alien who appears on the Joe Kubert cover of 1st Issue Special 12 (March 1976) is called Starman in the logo, but no one actually ever calls him that in the Gerry Conway, Mike Vosburg and Mike Royer story.
The character goes through much of the issue speaking his own language, unable to communicate with the inhabitants of Earth, and starts off having to fight to defend himself from them. He shows himself to be quite powerful, but still winds up collapsing after the fight.
Other blue skinned aliens have a base on the Moon, from which they are planning to invade Earth. From them we learn that the one labelled Starman is Mikaal Tomas, a rebel who betrayed them and went to aid the humans. Master Komak is in charge of the invasion, and he has summoned Turran Kha to find and kill Mikaal.
Mikaal has a dream, which conveniently fills in his side of things. We learn how the woman he loves was killed, and how this lead him to turn on his own people. He was sentenced to death for attacking the high command, but managed to escape.
A friendly couple take him in on Earth, and he learns English seemingly instantly. He explains his backstory to them, but they think he is crazy, until he jumps out the window and flies away.
The story ends with Mikaal and Turran Kha facing off for their big fight, but no direct follow up came. Other Starman came and went before, you guessed it, James Robinson revived the character in the 90s in his Starman series.