Well thats an easy one...

They would swim on shore like the Prehistoric fish, with a force field around them ( like the aliens in Independence Day ) immune to all types of fire and would just blow everything up!

Sorry Joe, I just couldn't help myself

__________________
The war against Russia will be such that it cannot be conducted in a knightly fashion. This struggle is one of ideologies and racial differences and will have to be conducted with unprecedented, unmerciful and unrelenting harshness. -Adolf Hitler