The Henchman 800 Unit is a Robo-Pirate unit that comprises the majority of the Robo-Pirate Army led by Admiral Razorbeard. They are most famous (and infamous) for being the most common enemy in Rayman 2: The Great Escape and especially its remake, Rayman 2: Revolution.
The ranks of the Henchman 800s is determined by color, though this isn't very noticable until Revolution, as color ranks overlap in Rayman 2. There are also many ranks that only appeared in Revolution and/or the PS version of Rayman 2. Rank strength can commonly be seen in how many hits it takes in Revolution to take down a Green Robo-Pirate, which then may be compared to the higher ranks.
Green Robo-Pirates are the lowest ranking Henchman 800 units, and are capable of being defeated in two hits by Rayman's original Magic Fist, and may be defeated in one hit after Rayman saves Ly the Fairy. They are the most common of the units in the beginning of the game, and later in the game are frequently paired with Purple Robo-Pirates--especially when ambushing. Green Robo-Pirates are first battled in the Fairy's Glade, and only appear in Revolution.
Green Robo-Pirates are inexperienced in battle and are usually easy to hit. Their lasers are in the form of orbs.
The Green Robo-Pirates are comparable to the Red Robo-Pirates that appear early in Rayman 2.
Purple Robo-Pirates are slightly stronger than Green Robo-Pirates, and can take three hits until Rayman saves Ly; afterwards, Purple Robo-Pirates may be slain with two hits. Used as guards in their first appearance in the Fairy's Glade, Purple Robo-Pirates tend to sleep a lot. They fire blasts like their green counterparts, but are more likely to hit their intended targets. Purple Robo-Pirates are also slightly harder to hit than their green counterparts. Ever since their first appearance, Purple Robo-Pirates have been found somewhere near Green Robo-Pirates--especially when ambushing. Purple Robo-Pirates appear in both Revolution and Rayman 2, though Red Robo-Pirates sometimes overlap their rank in the latter.
Blue Robo-Pirates are the lowest ranking of the more-specialized "upper" Henchman 800 units. Blue Robo-Pirates seldom appear in any of the games, and one is treated as a mini-boss at the beginning of the Lost Island. They are the first Robo-Pirates to appear in Revolution utilizing a drill, though "Purple" Red Robo-Pirates utilize them in the Bayou in Rayman 2.
The Blue Robo-Pirates use a hit-and-run strategy. They will rise from the ground, fire a few shots at Rayman, and then drill back down before Rayman can get them. However, there is a pause between their shots that enables Rayman a chance to hit them.
Blue Robo-Pirates require quite a few hits to be taken down in their first appearance; however, this number is reduced to about two or three un-charged shots after Rayman completes the Canopy.
Blue Robo-Pirates do not appear in the PS version of Rayman 2 due to the game's absence of the Lost Island.
Yellow Robo-Pirates are unique, specialized units comparable to the stronger Orange Robo-Pirates, and both only appear in Revolution. Yellow Robo-Pirates lack the blasters of their brethren; however, they more than make up for it with their unique barrage weapon. When Rayman is at a distance from Yellow Robo-Pirates, the Yellow Robo-Pirates will lob cannonballs up into the air. These cannonballs will then arc down and land wherever Rayman was when the cannonballs were fired. Upon impact with the ground, the cannonballs explode and leave a damaging patch of fire on the ground for a few seconds, leaving that part of the ground unsafe to touch. If Rayman is close to a Yellow Robo-Pirate, the Robo-Pirate will give up its cannonballs and reveal a hidden weapon: a flamethrower. The Yellow Robo-Pirate will spew a line of flames in Rayman's direction until he returns to cannonball distance.
Yellow Robo-Pirates are formidable enemies during their initial mini-boss appearance in the Bayou. They are used specifically as guards, as seen on the Lost Island and the Menhir Hills--spewing fire at anybody who approaches their location. However, following the Canopy these Robo-Pirates can withstand no more than three well-aimed shots from Rayman, and so are less of a threat.
Despite being the generic Henchman 800 color and the most common color in Rayman 2, Red Robo-Pirates are only a unique rank in Revolution and are just as typical as Purple Robo-Pirates in Rayman 2, overlapping the Green and Blue ranks every now and then. But in the end, Red Robo-Pirates are the highest rank in Rayman 2 (except for the PS version).
In Revolution, Red Robo-Pirates don't appear until they are found sitting asleep near Skull Cave, guarding the entrance to Whale Bay. This rank is the highest of the un-specialized units, and as such displays top-notch battle strategies and accuracy. Instead of firing small orb-like shots like its underlings, Red Robo-Pirates fire "wave"-like shots that make it easier to hit their targets. Red Robo-Pirates also utilize the drills used by Blue Robo-Pirates, allowing them to appear out of nowhere and get straight to battle. If Rayman is too close to a Red Robo-Pirate, the Henchman 800 will swipe its hook like a melee weapon.
Red Robo-Pirates (along with the Orange rank) exhibit the unique and powerful ability to learn from Rayman's behavior. If Rayman tends to jump a lot to avoid attacks, the game will adapt to this and later in the game Red and Orange Robo-Pirates will not only jump to avoid Rayman's attacks, but will also fire into the air in anticipation of Rayman's jumps. If Rayman tends to zig-zag through shots, Red Robo-Pirates will anticipate this and fire in front of Rayman's path. There are many ways the Red Robo-Pirates can adapt, which makes them all the more formidable.
Three or four uncharged shots are necessary to bring down a Red Robo-Pirate.
The highest ranking Henchman 800 and a Revolution only enemy, the powerful Orange Robo-Pirates are seldom seen up until the Rainbow Cliffs, when suddenly they become one of the most frequent enemies for the remainder of the game. Orange Robo-Pirates can do all the same strategy techniques as Red Robo-Pirates and can also swipe their hook, but are unable to fire the wide beams unique to the Red Robo-Pirates. Instead, Orange Robo-Pirates shoot heat-seeking missiles (similar to Shock Rocket in Rayman 3, complete with the same color association) that follow Rayman until they hit their target. This is a double-edged sword, however: Rayman is completely capable of tricking the missile into hitting another or the original Robo-Pirate.
Orange Robo-Pirates commonly fight in pairs (as first seen in the Precipice). Orange Robo-Pirates have the highest HP of all Robo-Pirate enemies in the game (other than Barrel Pirates), and it takes many hits to take them down.
Black Robo-Pirates (or "Ninja" Robo-Pirates) have the flamethrower abilities of Yellow Robo-Pirates, but also have the hook-using abilities of Red Robo-Pirates. Their most notable characteristic, however, is their teleporting capabilities. Black Robo-Pirates only appear in the PS version of Rayman 2 and in Revolution; in both, they are mini-bosses. The Revolution Ninja Pirates are the mini-bosses of the Precipice and the Echoing Caves.
For more about Black Robo-Pirates, see Ninjaws.