@381dbcc7: The Velveteen Rabbit is a children's book written by Margery Williams and published in 1922. The Skin Horse is a character in the book who is a wise old toy that has been loved and played with by many children.
One of the most famous quotes from the Skin Horse is: "Real isn't how you are made. It's a thing that happens to you. When a child loves you for a long, long time, not just to play with, but REALLY loves you, then you become Real."
The metaphor behind the Skin Horse is that love is what makes us real. The book is about the transformation of the Velveteen Rabbit from a toy into a real rabbit, and this transformation is brought about by the love of a child. The Skin Horse is the wise old toy who understands this and helps the Velveteen Rabbit on his journey to becoming real.