MJOLNIR - this is the war hammer of THOR, the god of lightning, thunder, wind, and rain. MJOINIR is the most feared weapon of the Norse gods. It was believed to be able to knock down giants and entire mountains with only one hit. When thrown, THOR's hammer would return to his hand after hitting its target. It is said that MJOINIR was used by THOR to slay JORMUNGANDR during RAGNAROK.
Sea going vessels were often mounted with a dragon or serpents head on the prow. It is important to remember that most people of the Viking age were very superstitious by our standards. The dragon head was simply to frighten away sea monsters and spirits. When approaching land the head could be removed to prevent scaring off the friendly land spirits