The Langoliers are creatures in the Stephen King novella of the same name. This novelle was included with three other novellas in Four Past Midnight released in 1990. They are depicted as ravenous fur balls with no legs and three mandibles. Their only form of sustenence would appear to be time. As time passes, they devour the universe that is left behind. The only way to come into contact with one is by being asleep as you pass through a time rift.
The Langoliers possess no visible organs besides skin, teeth, and mandibles. While the monsters described by Toomey in his father's stories had fur and legs, these creatures have an almost reptilian skin texture and no legs. Their means of locomotion is flight, but they possess no wings or propulsive organs making the nature of this flight mysterious.
The Langoliers' teeth are a silver color, with the consistency of liquid. In their jaws, these teeth rotate around the three mandibles and morph shape continuously. As they appear, they have no brains, no eyes, no sensory organs whatsoever, but still seem able to detect sounds and sights and hunt organic prey.
They are able to ingest all types of Earthly matter, as proposed by their action of consuming the entirety of passed-time. The question of their intelligence is almost unanswerable to its fullest degree, as so little factual information on these creatures has been presented on screen. However, a few things can be deduced from their behavior. When chasing Toomey, the Langoliers appear more curious than directly malevolent, despite their fearsome appearance. To clarify, they behave more like animals investigating prey than demons sent to devour lazy young men (according to Toomey). They chase Toomey persistently, even though they could have killed him in barely under a minute as shown when they bite off his leg in one swoop. Clearly, they aren't so single-minded as to kill him at the first chance.
The monsters were also featured in a television movie based on the novella.
The name "Langoliers" as it refers to these creatures was coined by Craig Toomey, the antagonist of the novella. As a child Toomey's father told him about furry monsters that would eat children who didn't behave, similar to the Boogyman. They supposedly lived in closets and possessed unnatural speeds to catch the children who tried to "scamper away." It is this name which Toomey and Dinah use to refer to the creatures who devour the passed-time, so the term is actually a misnomer. What these entities actually are and what they are called, if anything, is unknowable.