Hideo Kojima explains the inspiration behind the name Solid Snake

“Snake, having a soft and wiggly image, and Solid being the opposite. I wanted to put those two contradicting words together.”

Kojima talks about MGSV: The Phantom Pain - story, characters and closing the loop on the saga

Metal Gear Creator Reveals How Snake Got His Name - GameRevolution

Hideo Kojima explains the inspiration behind the name Solid Snake

How Hideo Kojima created the characters of Metal Gear - Softonic

Solid Snake, Metal Gear Wiki

Metal Gear Solid and the Real World, by Anish Bachchan

Metal Gear Solid (Video Game) - TV Tropes

Why do some of the games have Solid in the name if they are not about solid snake? : r/metalgearsolid

Hideo Kojima's Strange, Unforgettable Video-Game Worlds - The New York Times

How Metal Gear Solid 2 Started a New Era of Fan Backlash

Metal Gear Solid Poorly Explained by an Idiot