The Slug Digger is a special slug only available in Metal Slug 6.
A multi-purpose subterranean digger as well as a helicopter. It has retractable drills on the left, right, and bottom sides, which are used to drill into the earth, and sports two vulcan cannons, which can also be used to drill through things by firing bullets into the dirt. The players cannot get out of the Slug, neither can they perform the self-destruct attack with it. If the Slug Digger is destroyed, the player is killed, and they will have to respawn in a new Slug Digger. Its cannon shot is a mine that stays in place until an enemy touches it or it is shot. It is used to burrow down underground into the Invaders base.
|Mechanized||SV-001 (Metal Slug) | SV-001 Type-R | Slug Copter | Slug Flyer | Slug Sub | Astro Slug | Slug Gunner | Slugnoid | LV Armor | Walking Machine | Slug Mariner | Drill Slug | M-15A Bradley | Metal Claw | Forklift | Slug Mobile | Augensterm | Protogunner | Slug Digger | Slug Trolley | Slug Armor | Slug Gigant | Golden Slug | MS-Alice | Ball Slug|
|Animal||SV-Camel | Elephant Slug | Ostrich Slug | Donkey Slug|
|Other||Middle-Son 1986 | Middle-Son 1999 | SV-002 | Borobune Slug | Motorcycle | Regular Army Helicopter | Landseek | PA33-21 Boat | RA-TTT | Rootmars|