Life leading up to The Sims 2
In The Sims 2 for PC, the unborn alien baby of Pascal Curious will be born shortly after starting to play the household. Pascal Curious was abducted by aliens before the game started, and he is on his third day of his pregnancy.
When it is born, the baby will usually have green skin and black hair. However, it may have Pascal's skin tone. Most of the time, it will have black eyes, but it's possible for them to be dark blue like Pascal's.
Life leading up to The Sims 2 (PSP)
He is held in the Secret Sub-level in Division 47.