Atmospheric Anomalies, also known as Sky Beasts, are alleged creatures that fly through the sky, despite not appearing as aerodynamic, in Grand Theft Auto V. Reports include descriptions of flying jellyfish, freakish clouds, and floating graphical glitches.
Sky Beasts fly without any need for wings, and they appear intangible. Some claim that these may explain the UFOs seen throughout the game.
Descriptions of Sky Beasts vary, though some general themes stand out. One of the most common in GTA V is, that they appear to be bundles of disembodied textures floating through the sky. Because they actually do fly, and yet have no apparent animation, their motion comes off, as incredibly unsettling.
Another description of these anomalies draws a comparison to jellyfish if they were capable of flight. Again, it always appears as a 2D texture, rather than a fully formed, fully animated model.
A third description is one, that has less form than the flying jellyfish, but more of the disembodied textures, that of wave-like clouds that move inexplicably, and against the pattern of other clouds, sometimes going so far, as to follow the player throughout the map.