The D-Gu is a sentient clay object, exclusive to Metal Slug Attack. It first made its debut in the game alongside Caroline in "Ancient Code", although it was not playable as a standalone unit until "Task Force 5th".
First appearing in "Ancient Code", Caroline attaches a device on D-Gu so that she may control it. D-Gu is not happy at being controlled without its consent, but is forced to comply nonetheless because of the said device. It is used against the Regular Army, destroying a new Slug Square variant. Caroline's control falls temporary, but D-Gu concludes the battle before dragging Caroline deeper into the ruins.
It later manages to break free of Caroline's device, although Caroline is still attached to the weapon. A rampaging D-Gu is confronted by Rita, and although it puts up a good fight, it is defeated. Rita refrains from completely destroying it however, stating that she'll be more "serious" in her next encounter. D-Gu runs off from the defeat.
When used by Caroline, D-Gu is remote controlled. In this state, Caroline can order it to fire rock missiles from its bottom, and to advance forward and smash enemies, which also deletes non-piercing projectiles in two different move patterns; one a simple advance forward, and another violently squishing its opponents. If Caroline is defeated, she'll run away, but not before setting the D-Gu on a collision course up ahead to crash into enemies.
When it was on a rampage, D-Gu moves as if it has a will of its own. It still retains its long range attack, except the missiles are larger, stronger and cover more range. As its special attack, it generates a firestorm instead. It also retains its evasion capability, advancing forward before squishing enemies with its mass.
- D-Gu is shaped after a Dogū clay doll.