Appearance: A gruntan is an type of giant rat averaging about 7ft tall. Having a large cock that is a little more that a foot long. Looks obese in weight.
Great reference pic from redwall:

Physiology & diet: The gruntan body is a unusual thing. First is that for their girth they a startlingly agile and fast, capable of equaling an acrobat in prowess. Making catching prey much easier. The more they eat the fatter they get right? Sort of, a gruntans' body will reach a point where they will reach maximum size, and the energy from the prey they consume after that point will just add to their strength & speed. Gruntans also have several magical properties to them:
-Once their prey is fully enclosed in the penis, there is nothing they can do to escape
-Prey cannot suffocate or be crushed inside a gruntan cock, so they can masturbate their prey as long and as hard as they want
-They can teleport short distances (like past a door way that they cannot fit though)
-Drinking gruntan spooge will turn you into one, but you have to gain the weight on your own

Their penis is their most unusual organ. is quite large, and the sheath has fur. It functions like a snake of which it can stretch and swallow prey whole, as well as drink fluids. Most gruntans prefer to eat and drink only with their cock most of the time. Unless they want to get a lot of food down at once, then they will use their mouths and anus too. The dimensions are about over a foot long, and a little thicker than a soda bottle (24oz). Keep in mind due to the snakelike nature of the cock, it can stretch to much larger dimensions when consuming prey.
Their favorite prey is weasels because their long slender bodies are a perfect fit for their cocks, and particularly like the way they wriggle & sqrim helplessly. When a weasel is caught, the tip of the penis stretches open and begins undulating the unfortunate weasel down. When the weasel is all the way "in" the penis the gurntan usually starts masturbating with their victim inside. When the orgasm is reached, the weasel is swallowed down into the body to be digested. Or the scrotum to be turned into a gruntan's black, thick, and sticky (like honey) cum. They also have very large and efficient stomachs, capable of fitting over 2 dozen weasels, and digesting them all down to nothing in under a half hour. This gives them the potential to devour hundreds of weasels in a matter of days.

Every gruntan is a little different, but usually have one of four personalities :
Type A): The common gruntan pretty much.
Type B): "The slow rider" These gruntans like to take their time and spend dozens of minuets or even hours masturbating on a single meal. They are considered less dangerous due to the amount of time to go though one weasel.
Type C): "The horker" These gruntans don't care about masturbating and will just hork them down as fast as they can. Do the math and they are the most dangerous of all. Capable of devouring hundreds of weasels in a matter of days.
Type D): Somewhat friendly gruntans that don't digest their food. So they don't kill weasels, now whether they consume willing prey and let them out is a different story.

Gruntans also have this age old nursery song:
"All around the mulberry bush, the gruntan chased the weasel. The gruntan stopped to pull out his cock, Slurp goes the weasel!
Next the gruntans cock sucked him in. The gruntan liked the flavor. Then the penis sucked him deeper... Slurp goes the weasel!
The Weasel tried to scream and yell. The weasel tried to wriggle. Then the gruntans' cock swallowed him down. (on orgasm) Slllluuuuurrrrrrp. Goooeeessss. Theeee Weaaasellll."

I'll brush up on it soon, I have other things to do now.

HeeooooWeeee! I got a Critter crawl'n in me cock!
Behold the southern gruntan, very similar to a regular one, but is closer to the equator, has a southern accent, and instead of a rat it is an opossum.

The Gruntan and the Nightspears

"So how 'bout this?"

The mouse woman had a brave face on, but it was obviously a facade. "That - that is a cider that we received from - " She began, before halting herself as the weasel took a gulp of it. Almost seeing what was coming before it happened, she half-managed to shield her face as the weasel spat it out at her.

"Blech! You tryin' to poison me?!"

"N-no - please, we - "

She was interrupted by the barbed tip of the spear shoved inches away from her face. Her daughter began wailing again, as a mixture of panic and fear.

"If'n even one of the nightspears gets mad - just one of us - then you'll get the same fate as yer mate." He leaned close to the young one. "Cut yer caterwaulin'! That goes for you too!"

The young mousegirl shoved her face into a pillow as she continued to cry, her mother with one hand on her shoulder. "Please - you have taken everything you want. Just let my daughter go - she's just a young one!"

The weasel backhanded her savagely. "Can it! We'll leave when we're good and ready - maybe spend a fortnight with you two to host us." Reaching out, he grabbed her by her tunic, tearing it as he yanked her towards the door of what had been a comfortable living room before the nightspears had absolutely trashed the place. Everything was torn up, most of the cabinets and woodwork were broken, and overall the place looked like a tornado had gone through it.

Not that any of this bothered the weasels. The mother and daughter were yanked into the central room, to look at the chief of the horrible invaders who'd assaulted their quiet home - fat to the point where it was difficult for him to walk, the weasel chief was sitting on a chair that creaked under his weight, helping himself to their choice pastries. The mother noticed her husband was lying on the floor unmoving; she didn't have time to determine if he was breathing before she was forced to turn towards the chief himself.

"Keeping our hosts occupied, Kennel?"

Kennel gave a wicked grin, leaning on his spear. "They're reeeal generous."

The two snickered, as Kennel grabbed a muffin, popping it into his mouth. "Mrrfh Mmofy?"

"Sent him out with the rest 'bout an hour ago." The chief scratched his rotund stomach. "Where you find one family, you tend to find more nearby. We'll have enough vittles to last us for months!"

Kennel chuckled as well. Although given how much the chief ate, it probably wouldn't be that long - but that's plenty fine. He glanced around.

"...you sent Illen too, chief?"

"Nope."

Figured he wouldn't - Illen's job was to keep an eye on the chief. The chief grabbed the mother by her tunic, extracting a cry of surprise. "And we've got some other perks here, eh?"

"L-let - unhand me!" She shrieked, but she in no way had the strength to overpower the weasel chief. Kennel shook his head - chief had always had a thing for mousemaids - and stepped out of the room towards the entrance.

"Illen?" He called out, as he stepped through a couple doorways. "The chief was - "

In which he froze.

In which, well, there was Illen. He was plastered against a wall, face white from fear, hyperventilating as he was wont to do in any dangerous circumstance. But then again, this time he was well justified in reacting as such, as Match was also in the room.

Except all you could see of Match at the moment was his tail, as the rest of him was snugly wrapped in the long snakelike cock of a gruntan.

A gruntan.

Gruntans were the kind of bogeymen stories that weasels told each other over campfires. They weren't real - they couldn't be. If they were real they'd have vacuumed up all the weasels for miles, so they clearly weren't real, right?

Even though he was staring at one, it clearly wasn't real, right?

It clearly wasn't sitting right in front of him, tongue dancing along its lips in bliss, massaging its lengthy cock with both hands, muffled cries of Match from within it serving only to heighten his pleasure.

This wasn't real.

And thus he sat there, just staring at the enormous rat, who was more than happy to continue masturbating in front of the other two, for at least a minute or two before it occurred to him that he should react. "M-Match!"

Kennel dove forward with his spear - to find himself batted aside the way you'd swat any other insignificant fly that was bothering you. The Gruntan didn't even really move.

Standing, Kennel tried again - this time shifting his spear as he dove in low. Given the Gruntan's sheersize, there was no way he'd be able to -

- the thought was interrupted as the Gruntan grabbed the spear.

That was impossible. He'd have had to twist his entire body around while simultaneously having the right timing to grab the spear just behind the spearhead, as that was the only place outside of where Kennel was holding it that was safe to touch... and... and he'd... and he'd done that.

"Ha!"

First time the Gruntan had actually spoken. His guttural voice sent shivers up Kennel's spine.

"This one's barely struggling."

He patted his bulging cock, and the muffled squeals from within got more and more silent as the bulge became less and less pronounced. Finally, Kennel could only stare as what was left of the bulge sank into the gruntan's scrotum.

"So!"

Omigod he stood. How was he able to stand immediately after that? His enormous cock dripped just a tip of pre - and seemed to shift towards the - Kennel leapt backwards as the snakelike cock moved in his direction.

"Maybe you'll struggle more."

Kennel ducked into a roll, evading the Gruntan's lunge. It was insane - how was something that big thatfast? "Match! try - " He began before he noticed that the other weasel was not in the he threw himself flat to the floor and leapt up and scrambled forward.

The gruntan laughed, clearly enjoying himself. "Dodgy little bugger. Best type."

Unfortunately for the weasel, he'd gotten predictable. As he dropped again, this time the Gruntan was ready. One shift later, and he was firmly in the gruntan's iron grip. He grabbed the gruntan's hands to pull them away to no avail - it was like there was a vice clamped firmly about him -

- As the chief stuck his head into the room. "Ey! What's Match going on about?"

Kennel didn't even have time to shout a warning. For all his perks, the chief didn't have anything resembling the reflexes of the other weasels - the enormous rat had the weasel chieftain in an iron grip before the latter fully realized he was in the room.

"Knew if I let one get away I'd fish out more of you weasels."

The gruntan chuckled, as Kennel kept up his struggles. This was unreal - he was pretty strong for a weasel, but this giant rat had him firmly locked down with one arm, with zero effort spent keeping him put.

The chief was in a state of absolute panic. "Y-you're n-n-n-not r-r-real." He managed to splutter out, causing the gruntan to laugh, cock extending.

Kennel's eyes widened as the slit opened - wider than he'd thought was possible, even though he was seeing it firsthand. It engulfed the weasel chief's head, extracting a horrible wail from its victim. The cries went unheard, however, as the gruntan greedily slurped the weasel down. Despite being overweight, the chief was still very much weasel-like - and the gruntan gave a moan of pleasure as the relatively slender body almost oozed into the shaft, where it remained.

Almost as though he'd forgotten that he had Kennel tucked helplessly under one arm, the gruntan began massaging his cock. A single sticky drop of pre peeked out from his slit as he relished in the squirms and struggles of the weasel in his cock. He gave a content sigh as he masturbated further, the chieftain uncomfortable and stuck firmly, engrossed in the gyrations of the enormous maleness about him.

Kennel could barely breathe. The arm which had him in a vicelike grip was compressing his windpipe - he could only take quick breaths between gyrations. He tried to struggle more as stars filled his head - tried to push the enormous arm off him - as he managed to croak out, "Ch-chief-"

~~
Slowly, Kennel's eyes opened.

In which he jerked back to reality - he'd blacked out?! How long had he been out?!

He was still in the grip of the gruntan, but the grip was a lot more light now, enabling him to breathe. The gruntan's cock was moving around, as the gruntan poked at the bulge therein. At some point, he'd opted to sit down.

"Pah. Not even half an hour before he passed out." The gruntan sounded disappointed. He glanced at Kennel, who tensed. "...hope you go for at least an hour."

Kennel's shout of concern went ignored as his snout was shoved into the snakelike cockhead. It almost swallowed - no, it did swallow - gulping down the weasel's eyes and ears before slurping in his neck. He struggled - oh he fought it - but there was no slowing his progress.

His hearing was muffled by the undulating passage, but he'd swear he heard the gruntan give a moan of pleasure. He swore as he tried to pull himself back - to no avail. Slowly, his torso and chest sank in, followed by his thighs - as the world began rumbling around him. Sticky cum soaked into his fur as he felt himself pressed down and around - was the gruntan masturbating before he was even all the way in?

The gruntan twirled the weasel's tail as it slowly sank into his elongated shaft as he continued to massage himself. This weasel - now this weasel had a delicious flavor, and wriggled just right!

Tongue lolling out of his mouth, the gruntan leaned back as he continued to jerk himself off, intentionally losing himself in pleasure.

With a shout, the gruntan came - black sticky honey-like cum gooshing out of his cock like a firehose.

He continued to stroke himself as the stream slowed to a trickle. And, finally, his snakelike cock calmed itself, just a bit. Now that was a weasel - he'd gotten over an hour of masturbation out of him.

He liked spending at least an hour per weasel. No sense rushing meals, after all. He was a slow rider to the end - at least, when the weasel proved worthwhile. He wanted more like that last one - heck, he could still feel him even as he was being churned into additional cum. Hm.

And like that, he was in the next room. He could see from the tracks on the floor that the mice who lived here had escaped out their back exit; no big deal, he'd just had plenty of weasels, so who needs mice?

But that door - which had heavy things shoved in front of it - also had a ribbon tied on it. As if it was a wrapped gift.

And, as he approached it... he heard whimpering on the other side. Very familiar whimpering - the same as the creature who'd been nearly frozen in fear as he arrived. Another weasel - the cowardly nightspear... but who knows, maybe he'd last the full hour.

His cock began pulsing in anticipation, as the Gruntan licked his lips. There was always room for one more weasel.