In the Marvel comics, Peter Quill/Starlord is the son of J’Son of Spartax, but for the Marvel Cinematic Universe, director James Gunn decided to go another way by making Starlord’s father “Ego – the living planet,” played by Kurt Russell.
Director James Gunn has provided a few more details on what to expect from Ego, namely how exactly he goes about looking “normal” in front of other beings. Gunn said:
Ego is a living planet who is able to manifest himself in different ways he’s been alone for millions of years and he’s learned how to control the molecules around him in such a way as to create avatars of themselves, such as Kurt Russell. I think Ego was a very lonely character out there by himself and went off in search of love and perhaps found it in Quill’s mother.