The Soviet TYPHOON Class ballistic missile submarine (SSBN) was designed in the 1970s both as a counterbalance to the US Navy’s impressive Trident missile program and as a way of making the Soviet SSBNs more survivable by hiding them under the Arctic ice-cap. Nuclear submarines had been operating under the ice since the 1950’s, where they were found to be very difficult to track by satellites or other submarines using Sonar. In open water, the Soviet SSBNs could be followed by US and British hunter-killer submarines (SSNs) whose job it was to sink them before they launched any of their missiles.
Having run out of phonetic alphabet names to call new Soviet submarines, NATO opted for the TYPHOON Class SSBN (capital letters denote a NATO codename) because this is what the Soviet Leader Leonid Brezhnev called it. In the Russian service, it was known as the Project 941 Akula class. Akula means Shark and should not be confused with the submarine that NATO calls the AKULA. Originally ten boats were planned (a number discussed with the US), but only six were ever built.
Sources:
Sutton , H. I. (2020). The REAL Red October – Typhoon SSBN. Feb. 4, 2020. Accessed Feb. 2020 – https://www.hisutton.com/The%20REAL%20Red%20October%20-%20Typhoon%20SSBN.html