Akula, by an unfortunate coincidence (or possibly a clever gag on the part of well known Russian prankster Leonid Brezhnev), is also the Russian/former-USSR class name for the Project 941 ballistic missile submarine which has the NATO reporting name of Typhoon. The vessel known in the west as Akula, described in SkiBum5's writeup, is not the same machine, despite both being Russian nuclear-powered submarines; Russia calls that one Project 971, or Shchuka-B ("shchuka" is the Russian word for a kind of fresh water pike).

So the typhoon is really a shark, and the shark is really a pike.

This kind of thing is why some people say that military intelligence is an oxymoron.