Armless Biped

A creature with two legs but no wings or arms. May be used to make a creature look more alien, as the form is anthropomorphic yet easily falls into the Uncanny Valley. Or they make something appear harmless until it's too late. They can also be used to stylistic effect for cartoons with less realistic character designs.

While armless, such creatures may not be harmless (if you'll excuse the rhyme): They may still have a dangerous bite, kick or tail-whip/sting, or may have psychic or magical abilities.

Note that examples only count as this for species that naturally lack arms. That is, humans and other races that normally have them don't count just because of injury or a birth defect that caused them to be born without them.

Waddling Head is this minus a torso. May result in Invisible Anatomy.

Anime

 * Digitamamon from Digimon Adventure and Digimon Adventure 02.

Comicbooks

 * The Shmoo from Lil Abner.

Film

 * Shriekers and Ass-Blasters from the Tremors film series are built this way.
 * The Kaadus from Star Wars.

Literature

 * The Hammerheads in The Wonderful Wizard of Oz are armless, and attack by extending their necks (a la a jack-in-the-box).
 * The Carrion in Arcia Chronicles, an Eldritch Abomination summoned by the Gods of Light to devour the bodies of the slain Old Gods, consists primarily of a mouth and two legs.
 * The mecha from Orson Scott Card's Empire are pretty primitive, forcing them to use a simple spherical cockpit and dangerously unstable legs.
 * Because it is based somewhat on Empire, Shadow Complex also features these same mechas.
 * The inhabitants of Slongorn in the Well World series, although one could theoretically count their probosces as arms.

Other

 * Fuzzy only has feet. Acro conversely only has hands.
 * Several creatures in Wayne Barlowe's Expedition/Alien Planet, such as the Arrowtongue and Bladderhorn.
 * Many of Mortasheen's inhabitants fit this trope, the most recognizable being Chainsaw Kid.

Tabletop Games

 * Digesters, from Dungeons and Dragons, are portrayed a vaguely birdlike/reptillian bipeds with no arms. The run around spitting acid on things, and then slurp up the dissolved remains.
 * And then, there are the shrieker-esque ethereal marauders.
 * The eponymous critters from the board game Snits Revenge. They attack by kicking.
 * Warhammer and Warhammer 40000 feature Squigs, best described as half animal, half fungus, and half teeth. They're famed and feared for their unpredictable bounding gait and voracious ferocity, but Squigs form a surprisingly complex part of the greenskin ecosystem, serving as guard dogs, garbage disposals, livestock, and in one extremely specialized sub-species' case, hair plugs. Other races rarely appreciate this, however, as their encounters with the toothy critters come when goblins herd a bouncing horde of the things onto the battlefield, or orks strap them with explosives and send the beasts to chase tanks.

Toys

 * The entire Puffkins plush toy line.

Video Games

 * The earlier Oddworld titles have the Glukkons, bipedal suit-wearing executives. Their power lies in ordering mooks about.
 * oddworldwiki claims that they walk on their hands, and their legs have shriveled in disuse.
 * The ending of Oddysee confirms this. In a similar vein, there are the scrabs, centaur-style quadrupeds with human shaped torsos, but no arms.
 * The slogs are also an example of this trope, of a more canine variety however (basically big mouths with sharp teeth on a pair of fast, powerful legs about the height of a dog)
 * The Gekko of Metal Gear Solid 4 are depicted this way. And yes - . 'Armless they are not.
 * at one point.
 * The Goomba and Bob-Ombs from Super Mario Bros.
 * Bob-ombs do have a two-pronged windup key on their backs, which may represent the vestigial remains of forelimbs. If, you know, realistic evolutionary dynamics applied to sapient living bombs.
 * Paper Mario's credits depict Bob-ombs as having hidden white arms, though whether this applies to other games is up for debate.
 * In their first appearance in Super Mario Bros. 2, they did have arms, but by Super Mario Bros. 3, I believe, they had lost them.
 * Take-Minakata, a recurring demon in Shin Megami Tensei, has no arms.In mythology, his arms were cut off in a duel.
 * In the spinoff series Digital Devil Saga, Gale's demon form, Vayu, is an armless green creature which attacks by kicking with the bony blade on one of its feet. As does Harley's Hayagriva form.
 * Subverted. Vayu's arms are hidden by his wings (you can see them when he guards, uses an item or does his victory pose), and Hayagriva has T-Rex-esque arms hidden by little shell-thingies on his arms (observe when he uses Fire Storm or how he stands when he has Void Ice up). Dyaus would be a straigher example, because he has wings with tiny hands on the end of them.
 * In Spore, you'll usually have one of these at the beginning of Creature stage. Any more legs and you probably won't be able to afford many other parts. (Of course, you get an achievement for never using legs...)
 * The Headless from Pathways Into Darkness. This seems to show up a lot in horror. They consist of a gaping fanged mouth at about torso level with a giant tongue waving around in the air, they bend over to vomit green brains at you.
 * The monsters from the Dizzy spin-off Fast Food are this, in addition to being Waddling Heads.
 * The Silent Hill series has the Numb Bodies of 3. The first enemy encountered in 2, Lying Figures, can appear this way at a glance but actually have unusable arms bound in their own flesh.
 * Glaahks in Geneforge were genetically engineered as this for no apparent in-game reason, and out-of-game to make them absolutely weird. They attack with barbed tails, which are apparently coated in some kind of poison--a hit stuns you, and in a Solo Character Run two of them working together can prevent you from acting at all, wittling you down to nothing with you unable to respond.
 * Alits and Kagoutis in The Elder Scrolls III: Morrowind.
 * A few Pokémon have this body type, such as Oddish and Wooper.
 * Slavens and other same-class enemies in Final Fantasy XII
 * Metroid Prime has the Sheegoths, and its sequel has the Grenchlers. The Sheegoths are dangerous ice breathing predators who only have weakspots on their backs. Then you realise that they are the babies when you scan them - an adult one appears later, who is much bigger and meaner, and then becomes a Degraded Boss. Grenchlers look quite similar, except they're more like amphibian reptiles and are MUCH more aggressive and even more dangerous, with abilities Sheegoths don't, like firing electricity at long range and leaping across entire rooms. And then there's the one room in Dark Torvus with the Dark possessed Grenchlers, and the Grapple Guardian, which is another boss example.
 * Djinn in the Golden Sun games, which don't need arms since they can blast you with Psynergy or augment your powers.
 * The giant monster, the Imprisoned, that snatches Zelda in The Legend of Zelda Skyward Sword is basically a mouth with legs. No eyes. No nose. And covered in feathers that wave like fire on its back.
 * The Knife Thrower enemies in Psychonauts. How do they throw their knives if they don't have arms? With their feet, of course.
 * The player figure in Journey has no arms which was meant by the developers so people wouldn't wonder why they can't climb or pick things up.

Web Original

 * The title character from Homestar Runner, along with Marzipan, the King of Town, Homsar and a gaggle of minor characters.
 * Marzipan (and probably the King of Town) don't even have legs.
 * Milford Cubicle in Salad Fingers.
 * This is actually a plot point in the animated short Kiwi.
 * In Square Meal, you play as a troll that's one of these. It attacks by swallowing blocks (which comically distend it into a squared-off shape), then spitting the blocks enemies.
 * Raocow uses as his avatar: Demo, who is a blue-haired armless alien demon cyclops lady. Demo is also the protagonist in A Super Mario Thing.
 * Prowlies in Brackenwood.

Webcomics

 * In an homage/parody of the Goomba, Bogeys from Kid Radd the game in a webcomic are limbless.
 * The aptly nicknamed "Legs" from Schlock Mercenary.
 * Kind of- She does have wings, but they're entirely vestigial. Most of the time, She gets by with a cannon mounted on the back of her uniform, and her prehensile tongue.
 * Nagas from Crossworlds are, well, Nagas -- armless women with snakes instead of legs. They do just fine, however, as they're also some of the most powerful sorcerers in the setting, and use magical telepathy to simulate hands.
 * Doctor Disaster's simulation in Gunnerkrigg Court features the Enigmarons who somehow made a death ray and tied people up without any arms.
 * Beemahs from Buck Godot Zap Gun for Hire. They don't look dangerous for an engineered species of spies and assassin who made their creators completely extinct.
 * Dust Puppy from User Friendly. He is able to play Quake with his feet, and is very good at it.

Western Animation

 * Gagoyle from Inhumanoids. With a mouth that powerful, who needs arms?
 * The original designs for Mike Wizowcski from Monsters Inc. had him as one of these.

Real Life

 * The moas. Large, extinct ostrich like birds from New Zealand that completely lacked wings. Other flightless birds had their wings reduced to a few bones, but moas lost even the joints to which the wings were attached.
 * The modern-day kiwi has two very short stubs located where its wings once were, and are covered up by its thick, feathered body.
 * Snakes probably lost their front limbs before their hindlimbs- even today, you'll still find boas with vestigial pelvic girdles and even clawed 'spurs' where their hind limbs used to be. Although they never stood upright, so that probably doesn't count.
 * Abelisaurs such as the somewhat famous Carnotaurus were on the process of becoming this: Their arms retained a single spike-like claw, with the remaining 3 fingers being mere stumps, and their forearms became part of their wrist, reducing their arms to backwards-bending stumbs that were functionally useless and were getting smaller over time. Tyrannosaurs, however, were NOT going that route: The arms were reduced and had a finger less that the rest of advanced predatory dinosaurs, but they were also ridiculously strong for their size.
 * Inverted with frogs: when metamorphosing from tadpoles, their legs are the first things they gain upon reaching adulthood. They instead lose their tails.