Did this happen in Sims 2 or 3? you could eventually turn this doll into a sim. Only the child can see it. When they receive that "mysterious gift" in the mail.......I can't remember which one it was in 2 or 3?
That's a feature of the Generations EP. The Imaginary Friend is actually a (strange) occult state. But guess they are all pretty strange to us, come to think of it. ;)
I made one real once to see what would happen. I really don't like them, but they come with having kids and the kids love them so much- they function as babysitters always keeping up the social and fun. I'm always glad to see them go when the kid finally ages.
Poncho is his name. https://78.media.tumblr.com/eee0179e64615cf53fdeaf83852f9545/tumblr_p44np5cRd41ssiu0eo1_1280.png https://78.media.tumblr.com/908472538a985a1c42017646fd003c22/tumblr_p4j5uysZmo1ssiu0eo1_1280.png https://78.media.tumblr.com/68c926aba0f34a08294d577cef8942d9/tumblr_p4j5m8X86F1ssiu0eo1_1280.png https://78.media.tumblr.com/83ffa910eb4a5310f54673e96e6004fd/tumblr_p5ikzkghnN1ssiu0eo1_1280.png Only a couple of days before becoming a young adult. I have plans to make him a Magician. https://78.media.tumblr.com/8b8c9b82269c433cbbc66248c3da0a35/tumblr_p5ilpcufpC1ssiu0eo1_1280.png
Yes, they come with Generations and you can find more info here: http://sims.wikia.com/wiki/Imaginary_Friend