An ottery sleeping bag
Everyone knew about the big otters that swam and played in Wahachi lake. It was one of the lake's selling points and more people stopped by to camp, drift around in boats and watch the cute water-weasels swim and play than ever came to fish. That was just as well because a family of giant otters goes through a lot of fish (or a lot of fish go through a family of giant otters, rather) and even with stocking-trucks stopping by to add to the fish population on a weekly basis the pickings were pretty lean for fishing.
The biggest otters were more than ten feet from whiskers to tail tip and could easily overpower a human, especially one in the water, but they were in general perfectly safe to be around as long as you didn't do something stupid. Being stupid was how Billy got himself an otter-fur sleeping bag.
Late one night and after many beers Billy staggered away from the campsite and his passed-out drinking buddies in search of the campground toilets. Extraordinarily drunk and disoriented he ended up taking a leak against a tree and, had he known it, walking through quite a lot of poison ivy. This would have had itchy consequences later had Billy not literally stumbled across the otter.
Most of the lake otters denned up in dugout holts in the bank or in appropriated beaver dens (what happened to the beavers was best not considered, it was simply known that when the otters moved into a den all the beavers disappeared). Occasionally, though, the holt or den would be stuffed full of sleeping otters and the last one to arrive would find some bit of river bank to stretch out on. They were by far the largest predator in the region and no lesser beast with any sense gave a sleeping otter any trouble but Billy tripped over a thick otter tail and cursed drunkenly.
There was not a lot of moonlight to be had under the spreading limbs of the lakeside trees and Billy blinked owlishly at the long form stretched out before him. The big otter was still snoozing away and Billy staggered a bit further up the bank to look at it. A whiskery muzzle was now closest to him and the very drunk, very sleepy college student nodded. "Sleeping bag," he muttered, and clumsily sat down next to it to crawl in. He was wearing nothing but underwear (these sort of things make sense when one is powerfully drunk) and there was nothing to take off before going to bed.
Animal themed sleeping bags weren't unknown and Billy thought nothing of prying the broad whiskery jaws open and sliding his feet in. It was remarkably slick and warm inside and with the chill starting to creep through the midnight air Billy nodded happily and took a grip on each of the otter's cheeks to crawl further in.
The otter woke from a sound sleep and in much confusion to find a man stuffing himself down its throat. Billy had already slipped himself in all the way to his tighty whitie underwear and those caught for a moment on one of the sharp ottery fangs he'd somehow either missed so far or was too drunk to feel as they scraped his skin.
The otter lay there much puzzled as a man's hips were forcibly pushed into its maw. It was so confused that it lay silent and motionless, not sure if it was dreaming. It had swallowed very large catfish whole before but this fish was odd and lumpy and didn't taste quite right. But while the otter was befuddled its body wasn't confused at all by what was happening and its throat filled with saliva to lubricate Billy's slide.
The otter was lying on a slight slope and a gullet slick as oiled glass let Billy slip himself deeper with no resistance at all. Eventually Billy was to the armpits in otter and rolled onto his side to doze off, but even then he continued to slide down the slope and into the incredibly slippery otter throat. The only thing that eventually arrested his slide was the one arm outside the ottery sleeping bag. One elbow lay on the otter's furry cheek and Billy's head rested on a soft patch of moss just outside its jaws.
It wasn't to remain outside for very long. The otter was finally fully awake and though it wasn't quite sure how all this had happened there was a long bulge in its neckfur and chest that was beginning to get a bit uncomfortable. It could hold its breath a very long time but eventually it did need to breathe and currently its throat was stuffed full of extremely drunk sleeping man.
The whole process had been virtually silent and gentle so far and the otter instinctively kept it that way. Very slowly it opened its maw wider until Billy's elbow slipped in, and with a subtle forward wriggle and slight tilt of its head it accentuated the slope it lay upon. Sodden with ottery saliva and slippery as an eel Billy gradually sank into the waiting maw and throat, his shoulders visible as a thickening of the great bulge moving through the otter's neck. Gently and carefully the otter worked its whiskery muzzle upward over Billy's face until finally there was nothing outside the ottery sleeping bag at all but a single lock of hair atop the man's head.
It had its meal nearly swallowed and one gulp would send Billy down its throat even if he woke and struggled but the whole meal had been so peaceful that the otter didn't want to raise a fuss. All it did was lift its head to create a greater tilt and shift its forelegs a little farther apart so its chest had room to expand and gravity did all the work. The long bulge of drunken college student moved slowly out of its neckfur and into its body and soon enough Billy was stretched out in a lengthy otter stomach, too drunk even to notice the digestive juices that had begun to tickle his skin. Had he remained outside the ottery sleeping bag the poison ivy would have soon begun to itch but he was about to have other problems than itchiness and otters aren't affected by the stuff.
The long, streamlined otter now had a lengthy bulge in its middle but it was a very big otter and there was no one there to see the slight lumpiness to the bulge where hips and shoulders and head pressed against the oily pelt from the inside. A long burp vented the air that had gone down with its oddly willing meal and soon after that the air from Billy's lungs was belched up as well. So intoxicated was the man that he sank gently into unconsciousness in the wet muscular folds of the otter's stomach. The warmth and pressure squeezed the breath out of Billy and he never knew or cared that his sleeping bag was in fact an otter that had already begun to digest him.
The bemused otter licked its chops and returned to its peaceful slumber, and as the hours went by its powerful and rapid digestive system went to work on its meal. The long bulge in its middle slowly smoothed out its lumpiness as its gut gurgled and churned and by the morning there was no sign anything untoward had happened. When Billy's friends came stumbling hung-over through the woods to find him all they saw was a big sleeping otter that woke and blinked at them quizzically before sliding into the water. It was substantially fatter now, its body cavity full of mostly digested mush that used to be Billy, but not having seen the before and after there was simply no sign of their friend at all and no indication of foul play. All the evidence has disappeared into an ottery sleeping bag and neither the otter nor it meal was likely to tell anyone what happened.
The peculiar events of that night didn't change the otter's opinion of humans, that being that they were noisy and sometimes annoying but mostly harmless, but it did remember the taste and feel of an entire adult man sliding down its throat and if it occasionally lay near campsites, particularly those hosting drunken parties, stretched carefully out on a slope and with its muzzle invitingly open, it was hard to blame it.