Given a choice between looking at a completely new monster and one from the good ol’ days, I have a strong tendency to gravitate toward the latter, and when I wrote up a list of creatures from Volo’s Guide to Monsters and Mordenkainen’s Tome of Foes that I haven’t examined yet, one name jumped out at me: the leucrotta, which appeared in the original Advanced Dungeons & Dragons Monster Manual along with a much handsomer illustration than it’s given in Volo’s—but not nearly as hilarious a description. (Volo’s: “A leucrotta is what you would get if you took the head of a giant badger, the brain of a person who likes to torture and eat people, the legs of a deer, and the body of a large hyena, put them together, and reanimated them with demon ichor without bothering to cover up the stink of death.”)
I don’t recall leucrottas’ being associated closely with gnolls in the earliest days of the game, but in fifth-edition D&D, the connection is explicit: they’re another creation of the demon lord Yeenoghu. They’re smarter than the average gnoll and even smarter than gnoll pack lords, though not quite up to the level of a gnoll Fang of Yeenoghu. But they’re also less social, associating with gnolls mainly out of convenience and treating them as pawns when they do.
Leucrottas are large, fast, strong and tough—brutes, but unusually swift ones. They’re predators, but they lack proficiency in Stealth, which necessitates some creativity in their hunting pattern. How does a predator capture prey when it’s not good at hiding?
Well, let’s look at what the leucrotta is good at. Moving fast—its base speed is 50 feet per turn. Hunting in the dark—it has your basic 60 feet of darkvision. Melee attacking—it has Multiattack, and its Bite attack deals three dice of damage on a critical hit rather than two. Keen Smell—it doesn’t need to see you, or hear you, to know where you are. Rampage—like gnolls and their ilk, it gets bonus movement and another attack when it takes an enemy down. And Mimicry—it can imitate other creatures, including humanoids, with uncanny accuracy.
The solution I’ve come up with is very particular, but I think it works out. The central problem is that while the leucrotta can lure victims to it by imitating the sounds of an animal or person in distress, as soon as a victim got anywhere close to the leucrotta, they would immediately see the monster for what it was and hightail it. So how does the leucrotta avoid being spotted without proficiency in Stealth? It operates only in the dark of night, for one thing—but that only keeps it from being spotted by creatures without darkvision. What about creatures with darkvision, or with light sources? How does it get the jump on those? By exploiting another condition of heavy obscurity: fog. A foggy night is a leucrotta night.
Stealth and Perception are tricky, enough so that I devote a whole section to it in the revised edition of Live to Tell the Tale. The basics: If you win a contest between your Dexterity (Stealth) and an opponent’s Wisdom (Perception), you are “hidden,” i.e., both unseen and unheard, and your opponent doesn’t know where you are; it may not even know you’re there. Any break in line of sight—either a physical obstacle or an intervening zone of heavy obscurity—makes you unseen, which imposes disadvantage on attack rolls against you, but it doesn’t make you unheard. Thus, a foe listening carefully can pinpoint your location and aim at an attack at you, albeit with disadvantage. Darkness heavily obscures an area for creatures with normal vision, but for creatures with darkvision, it only makes it a little harder to see (disadvantage on sight-based Perception checks). Passive Wisdom (Perception) is on all the time and applies to all senses, so while you may have disadvantage on a passive check to see an enemy and fail, you may still be able to hear that enemy normally.
This combination of rules is what the leucrotta exploits. By hunting in fog, it ensures that even targets with darkvision will be unable to see it for what it is—and while they can hear it, thanks to Mimicry, what they think they’re hearing isn’t what they’re hearing at all. Plus, even if a target is hidden—unseen and unheard—the leucrotta can still locate them by following its nose, and it has advantage on that check, meaning that its olfactory passive Perception is 18. Yes, heavy obscurity effectively imposes the blinded condition on the leucrotta—but it effectively imposes it on everybody, and while a blinded attacker has disadvantage on attack rolls, attacks against a blinded target have advantage, and this advantage and disadvantage cancel each other out. Thus, the leucrotta is nearly guaranteed the ability to attack with surprise in the first round of combat, charging when it scents prey within 50 feet of it.
Kicking Retreat is the odd trait out in the leucrotta’s stat block. It seems not to be of much use for a creature whose ability contour clearly marks it as a brute attacker that wants to stay engaged in melee—and there’s never any need to Disengage in pea-soup fog, because you have to be able to see a foe to make an opportunity attack against it. This trait only comes into play if the fog is dispersed (say, by gust of wind) or if for some reason a leucrotta is hunting on a non-foggy night. (Maybe it’s found some convenient ruins with lots of fragments of ancient construction to block victims’ view.) Since it’s faster than almost anything that might fight back against it, it can begin its turn with a Multiattack, then use Kicking Retreat to Disengage as a bonus action and trot 40 or 50 feet away, returning on its next turn to brutalize its target some more. If you subscribe to the idea that leucrottas like to toy with their prey (I don’t, personally), Kicking Retreat also works for this purpose.
Predators are often dissuaded by prey that fights back and retreat after taking only moderate damage, but the leucrotta is described as being more bloodthirsty than most of its peers. It cares about self-preservation, but it won’t run away until it’s seriously wounded (reduced to 26 hp or fewer), and it uses Kicking Retreat to Disengage when it does so.
Next: cranium rats.