The Final Starman is an enemy from the Mother series, making its first and only appearance in EarthBound. It can be considered to be the successor of the Last Starman from EarthBound Beginnings.
The highest rank of Starmen, and all of Giygas' troops, Final Starmen are capable of performing very powerful PSI attacks, and as such, are encountered only in the final area of the game. They are encountered alongside other enemies.
In M.U.G.E.N, Final Starman has been made by Nazrin_no_otto (better known as Otto) as a boss character. For some reason, the character is named "Last Starman", which is a different enemy from EarthBound Beginnings, despite the character being based on the Final Starman from EarthBound.