One spectacular example is this Japanese white pine, on which the shaping work started over 600 years ago, during the time of Ashikaga Yoshimitsu, the 3rd shogun of the Ashikaga shogunate. Its location is at Kinkaku-ji, in Kyoto, on the place where originally stood the shogun's villa.
The pine was shaped like a sailing ship, with the crown suggesting the mast and one of the branches suggesting the ship. As you can see from the photo, because of its huge weight the branch is today supported by poles... a true living work of art...
EXIF info:
Nikon D90
Lens: 18-70mm F/3.5-4.5G
Focal Length: 29mm
Aperture: F/5.6
Shutter Speed: 1/80s
ISO Sensitivity: ISO 200