“I would love it if you could take a look at the umber hulk,” a reader writes. “It’s such an interesting monster to fight against.” I don’t know whether I agree with that—certainly, from a dungeon master’s perspective, it’s not that interesting a monster to run—but maybe the experience is different from the player’s point of view. Either way, the reader’s final point is beyond dispute: “Also, it penalizes characters who ignore Charisma.”
Based on its ability contour, the umber hulk is a straightforward brute: extraordinary Strength, very high Constitution, comparatively lower (though still above-average) Dexterity; its mental abilities are unremarkable.
It has nothing in the way of special skills, such as Stealth, but it has 120 feet of darkvision and 60 feet of tremorsense—the ability to detect vibrations through earth—and it can burrow at a speed of 20 feet per round. Even solid rock is merely difficult terrain as far as the umber hulk is concerned, thanks to its Tunneler feature. So a burrowing umber hulk can lie beneath the ground, unseen, waiting for prey to pass overhead, then make its first strike with advantage as an unseen attacker. Most likely, though, that first attack from hiding is the only one it will get.
It has a fierce melee Multiattack: two attacks with its claws and one with its jaws. But there’s no decision to be made there. The only thing that makes the umber hulk unique from a combat perspective is its Confusing Gaze.
Confusing Gaze isn’t an action, merely a side effect of fighting an umber hulk. Anyone within 30 feet of an umber hulk at the start of his or her turn, as long as it’s not incapacitated and he or she can see it, has to quickly avert his or her eyes or make a DC 15 Charisma saving throw against being boggled. The effect of a failed save is similar to that of a confusion spell: half the time, the umber hulk’s opponent just stands and stares, a quarter of the time he or she walks off in a random direction, and a quarter of the time he or she attacks someone at random.
Again, there’s no decision to be made here. A DM can run an umber hulk entirely on autopilot. But there is one interesting implication buried in the interaction of these features.
Darkvision and tremorsense imply a subterranean creature—one accustomed to fighting in total darkness. And remember, against a blinded opponent—that is, any player character without either darkvision or a light source—it gains advantage on its attacks, while the blinded foe has disadvantage on attacks against it. But anyone who does have darkvision, or who introduces a light source, is susceptible to the umber hulk’s Confusing Gaze. Damned if you do, damned if you don’t.
Thus, there are only two ways to fight an umber hulk without being handicapped: either have a very high Charisma and proficiency in that saving throw, or keep your distance and attack it from range. Naturally, the umber hulk ain’t having none of that. Its opponent retreats; it advances. It always looks to close to melee range with whatever enemy is nearest, without discriminating among them.
An umber hulk breaks off when seriously wounded (reduced to 37 hp or fewer). It burrows through loose earth to get away if it can, so that the earth collapses behind it (if it burrowed through rock, it would move too slowly to escape, and it would leave an easy-to-follow tunnel behind it). If that’s not available, it Dodges while retreating for a couple of rounds. It moves backward, facing its enemies, counting on the likelihood that its Confusing Gaze will disorient its pursuers long enough for it to get away. Whether that works or not, after a couple of rounds of Dodging, it switches to the Dash action.
Next: more constructs.