Vanguards are a modified version of the Crab-Tank, with two tentacles atop its carapace.Vanguards are able to fire oval lasers from its guns in the first segment of Final Mission, and the ones found deeper in the Invaders Hive fire a huge spinning laser from its eye, which can be hard to dodge. They are seen in Hard Mode only.
- The Crablops bears a strong resemblance with the Vanguards.
- In Metal Slug Defense, despite its different size, Vanguard is tied same strength as Mars Mecha and Iron Nokana
- In Metal Slug Defense, the sounds of the Vanguard are inverted, swapping the girating eye beam sound for the ray gun sound and viceversa.
- In Metal Slug Attack, the rarity of him is "Super Rare" and has AP tied with Slug Gunner, Mecha Allen, Regular Army Helicopter, Hairbuster Riberts, etc.
- When fully upgraded, Vanguard can shoot 4 Eye Beams all at once, and has a chance to knockback most units.
|Human||Rebel Infantry | Arabian Infantry | Division 6 | Pirates | Scientists | Ptolemaic Infantry | Natives | Hunters | Future Rebels|
|Undead||Mummies (Mummy Generator) | Dog Mummy | Mutated Soldiers | Zombies | Tar Man | Clones|
|Mutant||Bat | Chowmein-Conga | Ohumein-Conga | Enormous Moray | Jellyfish | Flying Killer | Man Eater | Huge Locust | Sasquatch | Maggot | Big Snail | Giant Caterpillar | Squid | Huge Ivy|
|Alien||Monoeye | Ring Laser Mecha | Hopper Mecha | Mars Mecha | Mars People | Big Eye | UFO | Mini-UFO | Invader Squad | Winged Invader | Flying Parasite | Hunter Walker | Hunter Lord | Scavenger | Crab-Tank | Vanguard | Smasher | Invader UFO | Indestructible UFO | Flying Core|