Forrest has the same facial structure as Amar Larrea. He can easily be cloned in Create a Sim with debugging mode on. Forrest is mostly interested in money and fashion, and he has a high level in logic.
Forrest shares his last name with Melissa and Kiera Fancey, but there's no evidence that he is related to either of them.
Warning
Do NOT attempt to add Forrest to a household, make him selectable, or tamper with him in any way or form. Doing so will corrupt the neighborhood he is in.