Question: The Guardians of the Galaxy, are a fictional spacefaring superhero team, appearing in American comic books published by Marvel Comics, it has an an initial roster, including which  fictional superhero appearing in American comic books published by Marvel Comics, where the character first appeared in "Tales to Astonish" #13 (November 1960)? 
Facts:
Guardians of the Galaxy (2008 team) is a fictional spacefaring superhero team
The Guardians of the Galaxy appears in American comic books published by Marvel Comics
Groot is included in the initial roster of the Guardians of the Galaxy
Groot first appeared in "Tales to Astonish" #13 (November 1960)
Answer: Groot