The human civilization took its most devistating blows after it lost control of the water ways. On land, man can fortify, he can use his surroundings to force his enemies to him, and he can escape and evade using skills passed down from caveman to modern soldier. That simply isn’t true with 70% of the rest of the planet covered in water.

Tetrapods serve as the main naval invasion forces of Cobra-La. They are able to glide through the water as fast as any submarine while also being able to walk on land for extended periods of time. Their bodies have been bio-engineered over a millenia to withstand the depths of the deepest ocean trenches which gives them the pure strength to rip the metal hull open of any ship. If you see one, you are in trouble because the others aren’t far behind.