Judging by Madame Foster's age, people have been creating imaginary friends for a very long time. We don't know exactly how long, but at least since before the 50's. A time period known for not exactly being PC.

That means there are probably imaginary friends based off of blackfaces and other racist imagery common during the Jim Crow era.

The question is, where are the racially-insensitive imaginary friends now? Does Foster's lock them up like they did with the scribbles? Or have they been banned from Foster's completely?