There was this movie I had watched when I was a kid.. It was about this famous actor, and I can't remember who. The guy made friends with an alein.. The lived with each other and became friends.. This alein was a man, but he had a baby. Then the alien dies and his friend took care of the alein baby?? I can't remember what this movie is called.

Were you thinking of the 1985 movie, enemy mine?

Yup it's Enemy Mine (1985) (http://imdb.com/title/tt0089092/)