Take a look at these inflatable sculptures on the New York City streets.
The artist is Joshua Allen Harris, he uses plastic bags (that he finds in the trash) to make all kind of animals. The plastic bags inflate when the subway passes under the grates. Real original and the subway line, which can not be seen in the steet, is made visible by his art.
There were a few of these near my old apartment. they’re so freaky. it’s awesome.