Scouting the wetlands

On the planet of Petrichor V, peace was, unfortunately, a rather shaky thing, many of the natives hardly hesitating to turn to violence at almost any provocation. Despite this, a sapient race had managed to emerge: The Lemurians, bipedal lizard-like creatures that were typically purple with a lightly-colored stripe along their front, and rarely seen without armor on their shoulders and hands. They typically lived in tribes of a couple dozen individuals, led by 1 or 2 Elders, Lemurians that, through an odd mutation, became yellow and grew to several times the average size.
Leskin was a member of one of these tribes, and was fairly average for a Lemurian, 6'9" and with a few scars. His role in the tribe was as a scout, often being sent out to specific regions for about a day at a time to see if anything unusual was happening in them, and report it if there was. While he wasn't the only tribe member with this job, the other had been out for 3 days at this point, and their absence was starting to cause some unrest.
Today, one of Leskin's friends had told him that the Elder wanted to talk to him. He wasn't about to turn them down, so after wrapping up the side job he was working on, he met up with the Elder, who of course wasn't hard to find, sitting at the edge of the small settlement.
"You wanted to see me, sir?"
"Good, you're here. Come with me, please, there is a rather urgent matter to discuss, and I'd prefer it remain private." The Elder stood up and started to walk, staying fairly slow so Leskin could more easily keep up, though he still nearly had to run to do so. With this kind of speed, it didn't take long for the two to be a decent distance from everyone else. "This should be fine", the Elder said, and sat down again, the ground rumbling slightly as they did. Leskin took a moment to catch his breath, and listened to what the Elder had to say.
"You know by now, Choll has gone missing. The whole tribe knows, and they're getting restless. So, I'm sending you out to look for him, in the wetlands where I'd previously sent him."
"There's more to it than that, right? Wouldn't make sense if you wanted that to be private."
The Elder sighed. "Unfortunately, you're right. Do you remember yesterday, when a messenger of another tribe came here?"
"Yeah, when you were done reading the letter, you... Burned it. I don't think you've ever done that before."
"It had information that would cause panic if it got out. I'm going to tell you what it was, but it must remain between us. Do I have your word?"
"...Of course."
Another sigh. "Acrid was spotted in the wetlands."
Leskin went silent. Acrid was the Lemurians' name for a seemingly-unstoppable beast that had terrorized them for the better part of a year, said to be able to effortlessly tear through groups of Lemurians at a time and look as if it was enjoying itself in the process.
"...Y-you're sending me w-where they might be!?"
The Elder gave a solemn nod. "I'm sorry. I wouldn't blame you for turning this down, but we'd have to relocate if you did. It's up to you."
After taking a moment to steady his nerves, Leskin gave his response. "...I'll do it."
"You're braver than most, Leskin. Thank you. Now, what I previously told you about your mission is all you will tell anyone who asks, and is technically true, but with some additions. Choll is almost certainly dead, but if they're somehow alive, bring them back home, and if they encountered Acrid, instruct them to tell me and only me. If they're dead, and you believe Acrid was involved, return immediately and tell me. Otherwise, search the region for any sign of them, and recover Choll's body. Do you understand?"
"Yes, sir."
"Good. If you don't come back in 3 days, I'll assume you're dead too, and the tribe will relocate. I'll leave behind directions, in case you just get caught up somewhere."
Leskin looked off in the direction of the wetlands, which would take him back through the settlement. "...If that's all, I suppose I should get going."
"Indeed. And, Leskin. In case I don't see you again, I want you to know I greatly appreciate all you've done for us. You and Choll would be hard to replace, and I truly hope you return."
"Thank you, Elder. I just hope that, if Acrid finds me, they at least make it quick..." Leskin returned to the settlement, packed up some supplies like usual, and, after telling someone he'd been sent to look for Choll, departed for what may have been the last time.

It took about half a day, but Leskin finally arrived at the wetlands. He normally liked this place, but certainly not with the threat of a nigh-invincible monster killing him for fun. After taking a break for a packed meal, he began his search proper. There was a lot of ground to cover, and even over the rest of the day, there was no sign of Choll, although he saw a few beetles and had a brief fight with a wisp. 
Eventually, night was falling, and Leskin now also searched for a place he could safely spend the night. Being experienced with wilderness survival, it didn't take all that long, finding a hollow section beneath a tree that was holding itself up with its roots. He took some time to obscure the entrance with some leaves and sticks, finishing the job from inside this makeshift shelter. Then, satisfied, Leskin relaxed, and fell asleep before too long, not really needing to be all that comfortable for that to be possible.
The night passed uneventfully, and after another meal, the Lemurian continued their search. A couple hours in, he found a set of tracks that, while old, were unmistakably from another Lemurian! He followed them, on and on, for another few hours, and eventually came to... A very dead Lemurian. Leskin could tell, this was Choll. Their tail and left arm had been torn off and were entirely missing, and what was left of him was covered in wounds from claws and bites. This was absolutely Acrid's doing, and Leskin had to get out of here.
Not long into his trip back out of the wetlands, in an area with water up to his knees, he heard loud crunching some distance to his left, as if something were eating something especially hard. Leskin paused for a moment to check what it was, and while it was a creature he hadn't seen before and had its back to him, he'd certainly heard of it. Red skin, spines seemingly randomly placed on their back, a short, stubby tail... Acrid. Leskin froze up, briefly just watching them sit and eat a dead beetle, shell and all. He'd be a hero if he managed to kill this thing, but he knew he wouldn't stand a chance, even if he'd gotten the drop on them as he likely could right now. No, he needed to go warn the tribe-
Snap! Not having been paying attention to where he was going, Leskin's heart skipped a beat as he stepped on and broke a fallen branch. Acrid turned their head, still chewing, and looked straight at him. Neither moved for a few seconds, and Acrid eventually swallowed the chunk of beetle in their mouth, setting down the rest of it and starting to get up.
Leskin screamed and immediately started to run, only managing to get a few steps before something slammed onto him, knocking the wind out of him in what quickly turned into a cloud of bubbles as he was forced underwater. He just barely stopped himself from inhaling, and was turned over to see that Acrid had pinned him! They grabbed him by his neck and lifted him from the water and above their head one-handed, the grip on his neck tight enough that he still couldn't breathe. Leskin tried his best to loosen Acrid's hold, kicking them and punching at their arm, but they didn't even react to it, just watching him choke.
As his face started to turn more purple than normal, Leskin started getting aroused. Lacking oxygen always did this to him, and while he tried to resist, his dick was starting to poke out of his slit regardless. He could feel himself just starting to weaken, his lungs burning, before Acrid suddenly loosened their grip on his throat. "KHUUUH! HAK, HUUU! S-SOMEONE HEHKH!" Hardly being given time to catch his breath, Acrid returned to strangling the Lemurian, and was now walking somewhere with him. This time, their grip wasn't letting up, and Leskin's attempts to pry their fingers from his throat accomplished nothing. His strength faded again, an arm eventually falling to his side, soon followed by the other. Too weak to struggle, the Lemurian hung limply in Acrid's grip, blue in the face but still barely conscious and now fully erect. Eyes rolling back and vision fading, Leskin's body shuddered in one last attempt to escape...
Then, he was tossed to the ground, and he could finally breathe again. "ghhiiihh..." Weakly at first, before hoarsely gasping and coughing, coming back to awareness. Acrid stood over him and watched his recovery, and Leskin looked back at them. Their 4 green eyes were practically piercing into his soul, and... He, as it seemed, was clearly enjoying tormenting the Lemurian, having gotten hard at some point.
Growling at him, Leskin's abused throat bulged out, and he shot a bolt of fire from his mouth at Acrid's face! He recoiled for a moment, then angrily grabbed Leskin by an arm and started dragging him toward a nearby pond, that seemed to have been what he'd been bringing them to while previously holding them. Leskin, having the feeling he knew why he was being brought to deeper water, struggled as much as he could, but was still powerless to do anything but slightly slow them down.
After getting close enough, Acrid threw Leskin into the water, jumping after them like he had before slamming them underwater and quickly adjusting to pin them on the bottom. He was heavy enough to pull this off, and while he couldn't swim or breathe underwater, he was tough, and could likely stay down longer than the Lemurian, who fiercely struggled to get him off them. Leskin could hardly move, Acrid sitting atop him and letting their weight hold him. All he could do was wiggle his feet and the end of his tail, looking up at the monster who'd started to masturbate while watching him hold his breath.
In just a minute, Leskin was already running out of breath, blushing from strain and arousal as his cock pressed against Acrid's butt. He looked up at them with puffed cheeks, hearing the occasional aroused, bubbly growl. Maybe he could outlast them, if he tried to stay calm? But, they didn't seem to be under any strain at all, yet... Still, he gave it a shot, closing his eyes and trying to focus on anything other than his lungs.
For a while, it seemed to help, and Leskin managed another minute before it started to be too much for him. Face going extra purple again and cheeks getting bigger as he started rebreathing in them, he lowered his head to try to press his mouth on something to help hold it shut. Upon seeing this, Acrid briefly stopped jacking off and grabbed Leskin's head with one hand. He looked up at them fearfully, bubbles being forced out his nostrils by his heaving chest. Then, Acrid held Leskin's jaw and forced his mouth open! A cluster of bubbles floated from his mouth and brushed past Acrid's face, the Lemurian struggling to not inhale.
It didn't take all that long. Unable to close his mouth, Leskin couldn't rebreathe inside himself, and soon couldn't hold his breath any more, audibly gasping a lungful of water. A couple clouds of bubbles were coughed out, and another breath taken, and Acrid released his grip, resuming his self-pleasuring as he watched them drown. Leskin thrashed what little he could, shaking his head and trying to stop himself from inhaling, but inevitably sucking in water anyway.
With his face now blue again, the Lemurian briefly held a breath of water, puffing his cheeks. His chest still jolted back and forth in repeated attempts to breathe, and his energy was still draining, so this hardly accomplished anything. At the same time, thought, his cock was throbbing heavily, the dire lack of oxygen turning him on like nothing else. It was to such a degree that he came just from that, the pleasure causing him to start trying to breathe again, each spurt of cum being accompanied by a gulp or hiccup.
Loving every second of Leskin's drowning, Acrid growled in pleasure again. The increasingly-distant expression on their face, the spasming of their climaxing cock against his ass... He found himself a bit jealous that he wouldn't get to feel what they did. Still, just seeing and hearing them was great, and he was getting close to an orgasm himself.
As Leskin came down from his orgasm, he felt exhausted. His body was going numb and he could barely move, taking shallow breaths of water and staring up at his killer, who was clearly still enjoying themselves. "...mnnguuugh..." He tried and failed to say something, then hiccupped again. Breathing started to take too much effort a few seconds after that, and his body gave up on it entirely, though it wasn't as if it had been helping. Vision fading, he could barely make out Acrid cumming heavily above him before his eyes rolled back. With another little shudder, he passed out at last, eyes still halfway open.
In the midst of a powerful orgasm, Acrid now jacked off with both hands in an attempt to further intensify it, repeatedly shooting cum nearly a foot ahead of him with a gurgled roar of pleasure. Not even realizing the drowned Lemurian wasn't moving any more, he continued to milk himself for a good 10 seconds more before his orgasm began to taper off, despite his efforts. He sighed out bubbles and released his cock, with just a few more throbs before his climax truly ended. It was typical that Acrid had especially large loads, but getting to watch something drown always made them even bigger, with this one having somewhat clouded the water in front of him.
Finally feeling the need to breathe, as he'd exhaled a significant amount of air, he got up off the Lemurian, picking them up and draping them over a shoulder. After a short walk, Acrid surfaced and gasped, making an attempt to shake off the water. He looked over at the blue face of the dead Lemurian he was carrying, remembering that they'd interrupted his meal. While he likely wouldn't be finding that beetle he'd been working on earlier, he preferred the taste of Lemurians to them anyway.