When we talk about the "other" in Death in Venice, we mainly have three characters in mind:
They all have something in common: There's something off with them. They are somehow strange, not unlike Aschenbach's "perverse" desire for Tadzio. In fact, these three figures embody the strangeness of that unsettling sexual desire.
The man Aschenbach finds hanging out in the graveyard in Chapter 1 is one of the first moments when the "other" steps out of the shadows of Death in Venice. Let's take a look at the first physical description:
The man—of medium height, thin, beardless, and strikingly snub-nosed—was the red-haired type and had its milky, freckled pigmentation. He was clearly not of Bavarian stock and, if nothing else, the broad, straight-brimmed bast hat covering his head lent him a distinctly foreign, exotic air. He did, however, have the customary knapsack strapped to his shoulders, wore a yellowish belted suit of what appeared to be loden […] (1.4)
One of the first things we notice is that this guy, as opposed to, say, Tadzio, is not described in very flattering terms. There's nothing here that gives us the impression of physical beauty. Instead, the narrator emphasizes the man's "distinctly foreign, exotic air," implying that he looks more out-of-place than anything else. And yet, his clothing appears typical for this part of Germany. He seems "other" not just because he is (literally) foreign, but because he communicates something strange and exotic within something that appears normal and everyday.
Having a hard time picturing it? Think: wolf dressed up in sheep's clothing.
Oh, and let's not forget that this is a graveyard. From the very outset of Death in Venice, the figure of strangeness and otherness is situated in a context that evokes mortality.
But let's keep reading. The rest of this passage reveals additional aspects of this "other":
Holding his head high and thus exposing a strong, bare Adam's apple on the thin neck rising out of his loose, open shirt, he gazed alert into the distance with colorless, red-lashed eyes, the two pronounced vertical furrows between them oddly suited to the short, turned-up nose. Thus—and perhaps his elevated and elevating position contributed to the impression—there was something of the overseer, something lordly, bold, even wild in his demeanor, for be it that he was grimacing, blinded by the setting sun, or that he had a permanent facial deformity, his lips seemed too short: they pulled all the way back, baring his long, white teeth to the gums. (1.4)
A few more things emerge from this description. First off, his "strong, bare Adam's apple" draws attention to the fact of his adult maleness—something that, again, we're not going to find in descriptions of Tadzio. Second, there's his "lordly, bold, even wild" expression, as he bares his teeth in what could either be a menacing look or simply a "permanent facial deformity." Not only is otherness hanging out in a place of death, then, but so, too, is ugliness.
But what if what Aschenbach sees here is simply an externalization of himself, his own hidden desires? (Have you reach Aschenbach's analysis elsewhere in this section yet? Because you totally should—it's a Freudian field day.) Maybe this guy represents all the forces in Aschenbach that are strange, frightening, and perhaps "deformed," which lord over him and threaten to get the upper hand.
What is clear, in any case, is that seeing this guy is what awakens in Aschenbach that "restive anxiety, a fervent youthful craving for faraway places," which sets the whole story in motion. This dude in the graveyard is really where it all starts—his ugliness sets Aschenbach off on his quest for beauty.
One of the most memorable figures in Death in Venice is the old man Aschenbach sees on the boat to Venice, who he discovers (with horror) is masquerading as a virile, young man. Of course, in one of the novella's many, ironic twists, Aschenbach himself will come to resemble this guy, when he dresses up and gets his make-up done to appear attractive to his youthful love interest.
Okay, before we get ahead of ourselves, let's go back to the scene itself. Lights, camera, action:
Once Aschenbach had had a closer look, however, he realized with something akin to horror that the man was no youth. He was old, there was no doubting it: he had wrinkles around his eyes and mouth; the matte crimson of his cheeks was rouge; the brown hair beneath the straw hat with its colorful band—a toupee; the neck—scrawny, emaciated; the stuck-on mustache and imperial on his chin—dyed; the full complement of yellow teeth—a cheap denture; and the hands, with signet rings on both forefingers, those of an old man. A shudder ran through Aschenbach as he watched him and his interplay with his friends. Did they not know, could they not see that he was old, that he had no right to be wearing their foppish, gaudy clothes, no right to be carrying on as if he were one of them? They seemed to be used to him and take him for granted, tolerating his presence and treating him as an equal, returning his pokes in the ribs without malice. How could they? Aschenbach laid his hand on his forehead and shut his eyes: they felt hot for want of sleep. He had the impression that something was not quite normal, that a dreamlike disaffection, a warping of the world into something alien was about to take hold […] (3.4)
This is the scene when it's all revealed—and Aschenbach is shocked and outraged to find out that this old guy is pretending to be young. He specifically questions his "right to be carrying on" the way he does, suggesting that Aschenbach perceives something morally wrong in this kind of behavior. Because, you know, Aschenbach is Mr. Moral Example… not.
But Aschenbach's reaction also seems to be physical; he puts his hand on his forehead, as if he feels feverish, and has the sense that "something was not quite normal." In other words, he's not just revolted by this guy, but something about him gives him the sense of a strange, imminent otherness, "a warping of the world into something alien." Pretty ominous, right?
Considering that Aschenbach will, in some sense, turn into this guy, it makes sense to think of him as embodying something that still remains buried or unconscious within Aschenbach at the start of the novella. (For more on the unconscious, be sure to read Aschenbach's analysis elsewhere in this section.) What makes this figure strange and "other" is not just his curious behavior; it's also that he taps into something not yet consciously realized in Aschenbach himself. So of course Aschenbach's all thanks, but no thanks about this dude.
The final character in Death in Venice whose otherness embodies perversity is the minstrel singer in Chapter 5. Take a look:
His build frail, his face gaunt and emaciated, a shabby felt hat pushed back over his neck and a shock of red hair gushing out from under the brim, he stood there on the gravel, apart from the others, in a pose of brazen bravado and, still strumming the strings, hurled his quips up to the terrace in a vigorous parlando, the veins bulging in his forehead from the strain. He seemed less the Venetian type than of the race of Neapolitan comedians: half pimp, half performer, brutal and brash, dangerous and entertaining. The lyrics of the song were merely silly, but in his rendition—what with the facial expressions and body movements he used, his suggestive winks, and the way he licked the corner of his mouth lasciviously—they became ambiguous, vaguely obscene. Protruding from the soft collar of his open shirt, which clashed with his otherwise formal attire, was a scrawny neck with a conspicuously large and naked-looking Adam's apple. His pallid snub-nosed face, its beardless features giving no indication of his age, seemed lined with grimaces and vice, and the two furrows stretching defiantly, imperiously, almost savagely between his reddish brows contrasted oddly with the grin on his mobile mouth. What made the solitary traveler focus all his attention on him, however, was the realization that the suspicious character seemed to bring his own suspicious atmosphere with him: each time the refrain recurred, the singer set off on a grotesque march, making faces and waving, his path taking him directly under Aschenbach's seat, and each time he made his round a strong smell of carbolic acid wafted its way up to the terrace from his clothes and body. (5.20)
Some of what we read here reminds us of the other "others" we've already encountered. Like graveyard guy, the minstrel has "reddish brows," a prominent Adam's apple, and the same snub-nose. And this guy is also described as a "half pimp, half performer," whose "suggestive winks" recall the same gestures made by the old man on the boat to Venice. What's on display in this character, then, is all the otherness that Aschenbach has encountered, wrapped up into a single figure.
This guy is, in a sense, everything that Aschenbach's trip to Venice has come to stand for in his life. In the last line of this passage, the marching minstrel disperses a "strong smell of carbolic acid," the disinfecting agent being used to combat cholera in Venice. This adds to the sense that the minstrel, in addition to embodying Aschenbach's own lascivious (a.k.a. naughty and lustful) impulses, embodies the debauchery of a "sick" city.
But for more on the way Venice gets personified, you're going to have to head on over to the "Setting" section. We'll meet you over there whenever you're ready.