Is It Possible to Cross-Breed an Ultra-Cow to Live Underwater?

Is it possible to cross-breed, for example, a beaver and an eel and an octopus and a whale and a cow to create a sort of ultra-cow that can live underwater? It's not really about fighting or violence. It's just about being large and creating a lot of beef. He was saying you could probably sort of fire it from a cannon at another country or from a submarine at a rival submarine. But no, can you sort of impress on him quite a lot? I think that's what the idea is.