The krayt started off as a pile of bones on Tatooine to showcase more of the exotic fauna of the setting, something George would show more fascination in as special effects advanced.
Here we have one of the first depictions of the krayt's bones, showcasing its long and large body with R2 standing at the front of its skull, who was originally supposed to be the one to find the skeleton rather than 3PO.
The skeleton itself was a massive prop made of fiberglass and was actually recycled from the 1975 Disney film "One of Our Dinosaurs Is Missing", with the skeleton itself being based on the
Diplodocus. Parts of this prop are still out there in the Tunisian desert where the movie was filmed, however like with most of the props left behind it has likely fallen into decay.
Small fragments of the skeleton though are preserved in a few museums dedicated to SW. Some are even sold online on occasion. Some people, for whatever wretched reason, tend to assume that JJ & Disney went back to Tunisia to restore the ruins of the ANH sets for IX, but that wasn't the case at all. They just remade it somewhere else and you can tell by some notable differences in the set and landscape. Anyway, despite the brief appearance of the skeleton in the film, an additional scene was conceived but it did not go beyond the initial sketches as seen below.
The krayt was intended to appear at later point to scare away the tusken raiders that were attacking Luke, but due to budget and time constraints, this never materialized beyond some basic sketches. However Kenobi's cry would still be identified as that of a krayt's within the novelization.
A krayt was also considered for ROTJ (pictured above as a maquette next to the old sketch) as one of the many creatures on Tatooine but was cut out due to constraints. Years later, McQuarrie would feature an up-to-date finalization of the low quality sketches along with many other concept art pieces from the other films and some new works also based on rejected ideas for the Illustrated Star Universe guide he worked on with Kevin J. Anderson which served as an in-universe guide to the main planets of the OT as told by an alien anthropologist named Hoole of the shapeshifting Shi'ido species. The finalized design was notably rounder and more plump than the original sketches, and while its hard to tell from the angle McQuarrie depicted it in, it seems to have a shorter neck.
Despite this, a krayt dragon based on the earliest sketches and maquette was depicted for the prequels' Wildlife of SW guide in 2001 as well as a trading card.
Having a more slender frame and a longer neck. Regardless, the original designs don't really match up with the skull or te length of the neck on the skeleton, do they? Thus in the same 2001 Wildlife Guide, the Krayt Dragon was divided into to two distinct species, the Canyon Krayt and the Greater Krayt, with the source implying that the canyon krayt may possibly a juvenile greater krayt but left it ambiguous to leave it open to the imagination.
With the Greater Krayt being presented as a more massive creature with 10 powerful legs and capable of 'swimming' through the sands and its skull matching with the one on the original skeleton, right down to the same teeth shape. The body of the Greater Krayt also served as the basis for the one used in the Mandalorian, however much of it is not seen and they took some rather phallic liberties with the head... The species was, at the time of the wildlife guide (2001), described as having many subspecies, all of them violent and
SW.com explained that researchers in lore believed them to be descendants of the precursor Star Dragon species (
which I covered a bit in my cosmic shitposts covering Supernatural Encounters). Despite this interesting rise in new lore, small details about the species were given as far back as the 80s, like the the SW guide released in 1984.
And for those curious about the krayt dragon pearl that appeared in the Mandalorian and its lore, the pearl originates from the 1997 Bantam novel Darksaber, where Han and Luke were able to sneak into a Tusken Raider camp, where Han's greedy eyes quickly took notice of the gleaming krayt dragon pearls, which the Tusken Raiders told tales of as having hunted for and even stolen from rival tribes. The pearls are essentially special unrefined stones swallowed by the krayts that over the decades become rounder and smoother and give off a strange energy while inside the krayt. The pearl's most memorable appearance would be in KOTOR, where the amnesiac Revan would help a Twi'lek hunter take down of these monsters and received its pearl as a reward (you could then choose to do whatever you want with it in-game, which was either give it to a Sand People tribe to recognize you as an honorable warrior, sell it for a heavy wad of creds, or turn it into a conduit crystal for your lightsaber). And finally, the Han Solo Trilogy (which take place before the OT) Han said that he had "found" a krayt pearl of his own which he planned to use to bet his way into the infamous sabacc tournament on Cloud City where he won the Falcon which replaced his first ship, the Bria (named after his ex-gf). Also of note was Darth Krayt, the main villain of the SW Legacy saga taking place 200 years after the OT who took Krayt as his sith name in honor of these beasts.
As a final note, here is a Greater Krayt fighting a Red Krayt which only appeared once in the SW RPG edition "Ultimate Adversaries" from around 2004.
And with that I think I'm done with the Krayts. Now onto the Millennium Falcon.