The Rebel Gigant is the sixth boss from Metal Slug 7.
A huge mech which was developed by the Future Rebel Army and brought into present day. It was specifically designed to be controlled by Allen O'Neil. Despite of its huge body and very tough armor it possesses great agility. It is also equipped with various weaponry such as homing missiles and floating mines.
Its attacks vary from firing rockets from the shoulder to jumping off screen and sliding into the player's Gigant. It is fortunate that death here allows another Slug Gigant to be employed after respawning (the Slug Gigant's destruction kills the player), as the Rebel Gigant would easily defeat the player otherwise. Note however it is possible to fight and defeat this boss on-foot using nothing but a pistol through a War Room mission.
|Ver. PM:: It has been somehow improved over its rebel counterparts. As its standard attack, it expels out 10 floating mines from its mine launcher, these mines will detonate when an enemy unit touches it or the set time has passed. Its special attack is an enhanced version of the original Rebel Gigant, the Rebel Gigant(P.M) crouches before charging forward, dealing massive damage against anything it hits.|
|Golden: The golden version whose floating mines from its mine launcher detonate burning fire when an enemy unit touches it or the set time has passed. Its special attack burns the ground by scraping with its giant feet, and also makes a red shockwave attack.|
|Original: The original variant ridden by Allen O'Neil himself, it appears in both Metal Slug 7 and Metal Slug XX.|
|MK II: The upgraded variant of the predecessor, ridden by an enraged Allen O'Neil, appears only in Metal Slug Attack.|
|Rogue Gigant: Another variant of the predecessor, this time being ridden by Allen Jr.. It fires red floating mines that emit fireballs instead. Only appears in Metal Slug Attack.|
|Element Gigant: Another variant ridden by Allen Jr.. It utilizes the Rebel Army "elements" of ice and fire in its attacks as requested by him. Only appears in Metal Slug Attack.|
- This is the only time Allen is not holding his M60 as a weapon, and has his hands on his hips.
- Though after he is defeated, he can be seen firing it in defeat.
- This is also the second time Allen appears as a boss, rather than this usual mid-boss status.
- In Metal Slug Defense. The Rebel Gigant was an unlockable unit in 1.32.0 Event world Release the Giant sleeping weapon. The Rebel Gigant's special move is dashing forward and crushing an enemy with its size, this attack appears in both MSD and MSA. The unit is now purchasable in the Shop for 500 Medals.
- Also, The Rebel Gigant's official name was confirmed in MSD 1.32.0 update.