(Btw spoilers for Metroid Zero Mission, Super Metroid, Metroid Dread, Metroid Manga, and More!, Please don't spoil yourself :D)
A Metroid Theory
Metroid: Why Kraid Is an Individual
Proof 1: Metroid Manga, Volume 2, Chapter 15, Page 12.
Mother Brain states that Kraid is Ridley’s comrade.
Proof 2: Metroid: Zero Mission Manual, Page 33.
The manual uses he/him pronouns for Kraid, and so does the manga.
Proof 3:
Kraid seems to recognize Samus in Metroid Dread.
Why the Kraid in Super Metroid Is NOT the Same One
Proof 1:
Just compare Kraid’s design in Super Metroid to his design in Zero Mission, the manga, and Dread.
Proof 2:
Kraid in Zero Mission, the manga, and Dread all share two side crests and one forehead crest. On the other hand, the Super Metroid version lacks a forehead crest and only has two side crests.
Additionally, the Super Metroid Kraid has an elongated head similar to Ridley (possibly suggesting Mother Brain used Ridley’s DNA to recreate him). Furthermore, the Super Metroid version has a bumpy back, unlike the spiky backs seen in Dread, Zero Mission, and the manga.
The horns also differ: in Zero Mission, Dread, and the manga, Kraid’s horns point backward, while in Super Metroid, they point upward. Finally, the Super Metroid version has a more upright posture.
Proof 3:
Building off Proof 2, the Zero Mission manual (Page 33) uses he/him pronouns for Kraid. However, the Super Metroid manual (Page 39) refers to Kraid as “it” and “the creature.” (Although Ridley is also called “it,” so this point may not be fully reliable).
My theory attempts to explain why this difference exists.
Kraid Timeline Theory
Kraid was either created by the Chozo (for unknown reasons) before Mother Brain betrayed them, or—more likely—created by Mother Brain after joining the Space Pirates. Another possibility is that Kraid is simply a member of a species that was captured or allied with the Space Pirates.
He either rose through the ranks to become a high-ranking soldier (possibly at the level of a general) and earned the title of Ridley’s “comrade,” or he was stationed on Zebes as a guardian. Either way, he was important enough to receive a statue in Zero Mission.
"Comrade" refers to a close friend, trusted companion, or fellow soldier, although Mother Brain also called for Samus to be Ridley's "Comrade" as well, so maybe "Comrade" just means same rank, in this sense, (IIRC Mother Brain didn't know of Samus' and Ridley's rivalry, so maybe she thought they would get along, perhaps),
Kraid was likely used as a brute-force combatant—a tank-like unit relying on strength rather than strategy—or as a guardian defending Zebes from “adventurers” (as described in the Super Metroid manual) and Federation forces.
During Samus’s raid on Zebes in 2075 (Zero Mission), she defeated many enemies, Space Pirate generals like Ridley and Kraid himself, although just like Ridley does, I think He survived, both in the manga and the game, he mostly dies off screen for the most part in Zero Mission, Kraid collapses halfway into the ground and explodes, but this may be more of a visual effect than literal disintegration. After all, Ridley has been “blown to smithereens” multiple times and still returns.
In the manga, Kraid’s upper body is seen on fire, suggesting he may have simply been incapacitated rather than killed. It’s possible the Space Pirates later revived him.
At some point, Kraid escapes Brinstar—though exactly how remains unclear. (No idea how he or the Space Pirates got his fat butt out of the caverns.
From here, things get more speculative, if you disagree or think he got captured another way, tell me! This is what sharing this is all about :D:
Perhaps the Mawkin Tribe scavenged Zebes after its destruction, but couldn’t fully explore it due to the damage from explosions (Mother Brains Self destruct, and the Space Pirate mother ship bomb). They might have discovered Kraid escaping and captured him.
Or after Zero Mission, the Space Pirates and Mawkin Tribe got into A Scruffle, and Kraid got captured, and even moooore crazy idea is that maybe the Space Pirates traded or sold, for something or... Someone, maybe Draygon! That could explain why a silhouette of a Draygon can be seen in Dread, IIRC, in a tank in the upper-left section of Dairon during a blackout, just a fun thought :D.
Regardless of how it happened, Kraid ends up in Raven Beak’s possession.
Around 2079 (Samus Returns / Super Metroid), Mother Brain and the Space Pirates attempt to recreate Kraid—possibly using Ridley’s DNA, which could explain the elongated head. This results in a clone (or multiple clones, like the Mini-Kraids).
This clone differs significantly from the original: it appears more animalistic, less intelligent (I don't know if the original Kraid was smart, but...), and less individualized—hence being referred to as “it,” “creature,” or “beast.”
These clones ultimately perish when Zebes is destroyed.
Meanwhile, the real Kraid remains imprisoned and experimented on by the Mawkin Tribe.
He later met Samus, his archenemy, the one he blamed for his capture and suffering, the one who made him be locked up on ZDR, the one who left him to rot here for more or less than five years, The One Who Ruined Everything. He trys to attack her, but his restraints are too tight, but you manage to still fight her and hold your ground, but alas, you fail. This is the (Hopefully) the end of my headcannon of Kraid's story.
And that may be the end of Kraid’s story—at least in this interpretation.
Thank you so much for reading! This is one of the first times I’ve shared a theory/headcanon like this, and I hope you enjoyed my take on Kraid :D, Have a blessed Day or Night :D.
(BTW: This is just my personal theory/headcanon. Please be respectful if you disagree! I do welcome constructive criticism, though—it helps me improve. I’d also love to hear your own headcanons! :D).