The Holoduke is an item in Duke Nukem Forever.
When used, the Holoduke creates a hologram that looks exactly like Duke. The hologram runs around and attacks any nearby enemy. Meanwhile, the player is cloaked, letting them line up a shot while the Holoduke distracts the enemy. Unlike it’s DN3D counterpart, it works on enemies, making it much more useful. It is known that it can be picked up and used whenever the player needs it.
The Holoduke has its own one-liners, parodying/misinterpreting those of Duke's, and speaks them in a robotic Schwarzenegger-like voice.
It is available in both single and multiplayer modes.