Master Necky is a large Necky who is the boss of the Monkey Mines in Donkey Kong Country. He is the second boss of the game and is fought in the level Necky's Nuts. In battle, Master Necky spits coconuts at Donkey Kong and Diddy Kong, who must defeat Master Necky by jumping on his head five times. Master Necky's whole body is never revealed; only his head appears on the screen.
In the Game Boy Advance port, Master Necky turns bright red before and after he attacks, becoming temporarily invincible. The Kongs cannot damage him until he spits out a coconut, showing his normal color, but he turns red again as he leaves the screen. Master Necky also joins Master Necky Snr. in battling the Kongs in the latter's level. Both must be jumped on five times to be defeated—when either boss is first defeated, the other Master Necky starts spitting four coconuts in succession. After defeating both bosses, the Kongs can battle King K. Rool at Gang-Plank Galleon.
Master Necky, along with Master Necky Snr. and Krocheads, only have their heads shown in the Donkey Kong series and no other part.