4-9

4-9 can refer to the following:
 * Level 4-9 from Mario & Wario
 * Stage 4-9 from Donkey Kong for the Game Boy
 * Fury Volcano 4-9 from Super Princess Peach
 * Room 4-9 from Mario vs. Donkey Kong 2: March of the Minis
 * Bowser's Castle, World 4-9 from Mario + Rabbids Kingdom Battle