Why is Metal Gear's Solid Snake called 'Solid Snake'?

In a series of Twitter comments, Metal Gear series creator Hideo Kojima offered up answers to the mystery of why franchise protagonist Solid Snake is called Solid Snake — and apparently it isn't a reference to Escape from New York's S.D. Bob "Snake" Plissken.

The use of the name "Snake" was "the most appropriate symbol of living thing that hides his presence and sneaks without any noise," wrote Kojima.

"The reason why I didn't use any specific snake names like cobra, anaconda or viper was because the protagonist is the player. The reason I use Solid was to give opposite impression of soft image," he continued.

"Like for of all endings of the any series, the appearance of strongest enemy was a must in Metal Gear Solid. It's the Snake who can surpass the Snake. Thus I brought about a ‘clone.' The struggle between SOLID and LIQUID. That was Metal Gear Solid.

"As I developed a sequel, a third snake was needed. Since both solid & liquid express an actual natural state. Obviously the next would be "gas" but Gas Snake would be like a human made of gas, and that's not a nice name. So I borrowed from the physics terms ‘solidus/liquidus'. SOLIDUS is not a real state but indicates the border between liquid and solid."

The Metal Gear series began in 1987. The series continues on March 18 with Metal Gear Solid 5: Ground Zeroes, the standalone prequel to Metal Gear Solid 5: The Phantom Pain, will launch for PS3, PS4, Xbox 360 and Xbox One.