Haku gritted his teeth as he backed away quickly. "Are you kidding me!? Since when can worms get so big!?"
The creature before him hadn't fully emerged yet, yet it already measured at least a hundred feet from head to the base of its body as it emerged from the sand. It was completely naked and tapered, like any worm, with the difference that in this case it was huge and yellowish in color to better blend into the sand. The beast moved its head, which was completely devoid of eyes, ears and nose and seemed composed only of a fleshy tip which made it more like a tail; then suddenly the head shook and split into four parts, revealing that it consisted entirely of one huge mouth. The four open jaws gave it the shape of a disgusting flower of flesh and had conical structures similar to teeth, which however didn't appear to be very resistant. As soon as the mouth was fully open, a scream emerged from within it with incredible intensity.
Haku had rarely heard a creature make such high-pitched cries. It was such a loud noise that at first it sounds like thunder. The strength of the sound was such that Haku's limbs started shaking slightly from the sound wave. The only creatures Haku knew could make such loud sounds were… well, dragons.
The worm made two more cries, turning its head in different directions. It was then that Haku put the pieces together. "It has no eyes... it's looking for me using sound vibrations!" he exclaimed. It wasn't the first time he'd seen an animal make use of sonar, but he certainly hadn't expected it from a worm.
The worm's head turned to him. It had found him. It opened its mouth even further and with a guttural sound something emerged from it: it was two huge retractable jaws similar to scythes, which widened until they came out completely from the jaws, and positioned themselves on the sides of the head. Then the worm began to slam them against each other making a rhythmic sound, similar to a chain dragging against a rusty iron block.
Haku grit his teeth. If the worm had hit him with those kind of scythes, it would surely have seriously injured him. They were large enough to hit most of his body, though not enough to completely sever him in two, and given the speed at which they moved, they must also have considerable strength. He had to play his cards right; he couldn't lunge at his opponent head-on this time. The worm had size and strength on its side, but it was completely blind and didn't appear to be very intelligent; Haku had every chance to screw him over, he just had to take them.
The dragon in turn opened his jaws and also emitted a sharp cry; the worm, hearing it, began to fidget and sway as if it were drunk. Since sound was its main source for orientation, and its sonar relied to making sounds which then bounced off objects and returned to the sender, the fact that Haku was making a louder sound than its was practically making it 'blind'. The worm tried to make louder sounds, hoping to drown out those of the dragon, but it couldn't. Even though the worm's call was loud, there was no way it could overcome the powerful vocal chords of a dragon.
Haku took advantage of the fact that the worm was disoriented to approach and with a leap jumped on its body, right at the point where it began to emerge from the sand, and bit it and clawed it with ardor. Even if the worm was huge, its body was still devoid of bones and protections and mainly composed only of skin and muscles, very easy to tear apart. Haku tore off a large chunk of flesh from the worm, which squealed in pain and then it thrashed violently, forcing the dragon to let it go and retreat.
The worm completely emerged from the ground, raising a cloud of sand, revealing itself to be even more enormous than Haku imagined. From head to tip of tail (if you could call it that, since the worm's body was all the same) it measured at least a hundred meters, maybe even a hundred and fifty. Its size wasn't that big if you looked at its total body mass (it was still a worm, so it shouldn't have weighed much; Haku doubted that, despite its impressive size, the creature could outweigh him), but if you only looked at the length then it was really enormous. Haku ascertained that that worm must have been at least as long as his deceased mother, even if it weighed so little that she could use it as a scarf.
The worm squirmed, hitting the ground with its long body and emitting various vibrations, kicking up clouds of sand in every direction. It was clearly trying to disorient him. Haku readied another attack, but before he could act the worm inflated what was probably its throat and then it pointed its mouth upwards, spitting out a large amount of smelly yellow liquid. Haku ran away, fearing it was poison, but he quickly realized it was just gastric juices.
Something was wrong. Such an attack was patently fallacious: even assuming that the gastric juices of that animal had some corrosive properties, why had the worm spat them up? Why hadn't it just pointed at Haku and spat at him, with a greater certainty of hitting him? This didn't make sense from Haku's point of view. It almost seemed that the goal of the worm wasn't to hit him at all...
Well, that didn't matter at the moment. Haku knew very well what to do: taking advantage of the fact that the worm didn't seem to move too quickly, he ran towards the wound he had already opened and as soon as he was close enough he used a fire rune to burn the worm from the inside. But the worm must have been smarter than Haku expected, because it noticed his movement and ducked violently, hitting the sand with his head. Haku withdrew and watched the worm wrap around itself to protect its wound. Even that attack didn't make sense: the worm had clearly hit the ground too hard not to hurt itself, and indeed it looked quite dazed now, and one of the two scythes in its mouth had snapped. its behavior was completely illogical to say the least.
A thought crossed Haku's mind. "This isn't a hunting behavior... you're trying to scare me! You think I'm a sand shark!"
Of course, it was obvious! How had he not thought of it before? The worm had never attacked him head-on, it only made loud noises and displaying its pincers in an attempt to appear more dangerous. It thought that Haku had come there to confront it... and it was probably Haku himself who made it think that since he practically chased after it. And since the worm had never encountered a dragon, it must have switched Haku with a similarly sized creature it knew... a sand shark.
Now it was all clear. That's what the prey of those strange fish was... that's why they hunted in packs! Because sand sharks preyed on those worms! And by the same token the worm had spat its digestive juices into the air, expecting to strike a pod that didn't really exist, since sand sharks hunt in packs... and it had struck the ground with that violence to emit a vibration that would disorient the fish, as they swam in the sand…
Haku almost laughed. That worm was trying to scare away enemies that didn't even exist! Even though he knew it wasn't its fault, he still found it hilarious.
Based on this logic, if Haku had now withdrawn the fight would have ended: the worm wouldn't have tried to chase him, since it thought him a predator, and would have returned under the sand where it came from. However, Haku didn't want to let it go; even if he hadn't come here for that particular reason, he still wanted to kill the worm and then analyze its body to find out what it could offer him. After all, that worm could guarantee a lot of meat... and then Haku wanted to open its stomach and find out what it fed on. In fact, the teeth of that creature didn't seem too strong, a sign that they shouldn't have been used for hunting; on the other hand, there shouldn't have been enough resources in the desert to support such a large animal. It was almost certainly a herbivore; so where did it find the flora to feed on? Since it too moved in the sand, it was likely that those food sources were underground, in the water system that Haku was now sure existed beneath his feet. To find out, however, he would have to at least understand what the worm was feeding on… which, in simple terms, meant analyzing the contents of its stomach. An operation that clearly couldn't be done on a live animal.
Or maybe yes? A new plan began to take shape in Haku's mind. It wasn't necessary to kill the worm: if it looked like the little worms he normally saw crawling on damp soil, then it should have survived even if cut in half. This meant that while he could keep a piece of the body for himself, the other part could survive... and by letting it go, Haku could then track it by smell and be led to the place where he was feeding. Or perhaps he could have done even better... the plan was taking shape very well in his mind, and Haku was more and more convinced that he could get a lot out of that story.
However, cutting this worm in half wouldn't be like cutting normal worms in half. Even if their body structure had been exactly the same, normal worms were extremely small, about eight inches long at most; which meant their blood vessels healed quickly and they weren't in danger of losing too much blood. But that giant worm's blood vessels must have been very large, or they wouldn't have been able to carry blood to every corner of its enormous body. Which meant that if Haku cut it in half he would surely cause it a fatal hemorrhage, which wasn't what Haku wanted. Therefore, before letting the worm go, he also had to heal its wound to ensure it survived.
He knew exactly how to do it: from his dimensional bag he extracted two healing potions and poured their contents into his mouth, being very careful not to drink it; after which he ran again towards the open wound he had created on the worm's body. It tried again to stop it by banging its head on the ground, but by now Haku had learned his technique and easily avoided it, and reached the wound which, with his claws, he enlarged so much that finally the worm's body broke into two pieces. A gush of blood sprayed his face, but he ignored it and forcefully spat the healing potion onto one of the worm's two ends. Within seconds, the blood stopped flowing from it and the skin healed. On the contrary, the other piece continued to bleed and toss; just like normal worms, once cut in half, the headless extremity apparently continued to move, creating a new individual. However, Haku paid no attention to it: the blood loss from that side was too much and it would soon die anyway.
The part of the worm that was healed and still had the head, which was now 'only' thirty meters long, lost no time and ran away: as Haku had foreseen, the worm must have thought that now that its opponent had something else to eat it wouldn't pursue it anymore. It moved its body as if to make a leap, but then it closed its big mouth and buried its head in the sand, moving like a snake and digging down almost vertically.
That was exactly the moment Haku was waiting for: while the worm was still digging its path in the sand, the dragon ran beside him and engraved some earth runes on his paw; as soon as the worm was fully introduced into the ground and the sand began to collapse from the sides, Haku ran around the hole that had just formed and hit the edges with the runes, making the sand extremely hard and thus preventing it from falling and closing the hole.
Haku continued to use numerous runes until the worm reached the hard rock and disappeared under it. At that point the dragon calmed down and looked satisfied at the deep hole that had just been created and which gave him free access to the subsoil. "Thank you. Now I know exactly where to go to know where you feel safe" Haku murmured amused, then he looked at the other piece of the worm, which by now had completely stopped moving due to too much blood it had lost. He could call it a total victory. "First the sand sharks, and now a... sand worm? Yes, I think I'll call it that while waiting to find a better name. This desert is turning out to be full of surprises"
Satisfied, he turned the communication device back on and said: "Isaac, tell my siblings to come here, and to bring Zamor and the other beastmen chiefs as well. I've found something very interesting"