World 2 (Super Mario Bros. 2)
From the Super Mario Wiki
World 2 (known as Chapter 2 in Yume Kōjō: Doki Doki Panic; also known as the World of Deserts) is the second world of Super Mario Bros. 2. The world has a desert and pyramid theme to it, which is later revisited in World 6. It is in this world that the player meets for the first time the Cobrat, Pokey, and Panser enemies, as well as their first boss fight against Red Birdo, who can spit fireballs as well as eggs. The main boss of the world, fought at the end of World 2-3, is Tryclyde, the three-headed snake.