i passed this deborah butterfield sculpture
in sfo back in december.
the horse is bronze but looks like driftwood. stanford art museum notes that "the technique used to make the sculpture is especially noteworthy for its convincing simulation of the texture, shape, and color of the wood." which increases the impulse to touch the sculpture. at stanford, they have a separate piece of the bronze driftwood for people to touch.
at the airport, seems people wanted to ride it. so much so, that they added a sign.
check here for an image search for deborah butterfield.