There was a doll on The Island Of Misfit Toys that seemed normal. I found out the truth in the Wikipedia entry which I linked too...
Misfit Dolly, or "A Dolly for Sue (as she calls herself)" is a seemingly normal girl rag doll with red hair and a red gingham (checkered) dress. Her misfit problem is never explained on the special, but was revealed on NPR's Wait Wait… Don't Tell Me! news quiz show broadcast December 8, 2007. The show says that when Arthur Rankin (Rudolph's producer) was interviewed, he said Dolly's problem was psychological, caused by being abandoned by her mistress and suffering depression from being unloved.
How were we sposed to know that?
They should've shown her popping Prozac.
At the very least, they could've had her wandering the streets asking strangers, "Are you my mommy?"