This is a French zinc finial commonly found on roofs. 
Glorious in its style and size making a fabulous statement and a conversation piece. These are sought after for gardens and interior decor and this one is particularly unusual in its design and extremely rustic   
It has losses due to its long age, it has lost one of its horns over its life, however nothing that takes away from how striking it is. 
Measurements: 23 x 85cm high