Gravituy

Describe the most dangerous apex predator in your world.

   Many large predators on Sharitarn have some level of resistance against magic, as you would expect. A fair number of them also have some natural ability similar to magic spells. Teleportation, pass through solid objects, telepathy. Among the most feared monsters are some originated on Universes where there is no light, where stars are made of dense Evil, and that is not a concept but a physic reality able to affect matter, and feed life. There is also huge beings almost impossible to kill, that need no food or water for stay alive and change the atmosphere just for being present: Altair calls those being kaiju. There is a nocturnal predator considered so wicked and vile by the Sharitarnes that speak its name in social occasions is considered insulting and obscene: the zudras.        On distant dungeons hunt the "yogurt dogs", perfect hydrous with color and consistency of natural yogurt that often assume a shape that remind dogs. They dissolve living things that came in contact whit them, and are barely impossible to stop or destroy. Never giving up, their only weakness is being poor climbers.         Intelligent species, "talking species" as the locals say, are often the most dangerous ones. And in that category the humans are by far the most dangerous. Thanks to their supremacy in the realm of magic. 
    Putting aside the intelligent beings, and considering individuals instead of collectives, my choice for most scary nightmare_and apex predator_ has to be the gravituy.  
     Those monsters look like dark clouds at distance, with lightning bolts inside them. But they are more compact and move faster than clouds. The specie controls gravity, and advances over a territory pulling all living things to it with enormous strength: animals and threes fall up in its direction to be completely destroyed. It brakes living tissue, molecules and atoms. 
      No one understands why it prefers to consume life, when non-organic matter should provide about the same energy. Must be some instinct originated in a Universe where the physical constants where nothing like what exists on Sharitarn, and where this behavior was reasonable.            One scary aspect of the Gravituy is its effect on magic users. Sigraxes became useless, mages have a chance to hurt the monster and scary it away but only if they act fast and from distance. Once it comes close the anti-magic field acts on mages like narcotic drug affect normal humans, and the most powerful a mage is stronger he is affected.  
       Fortunately gravituy don't seem to change their distance from the ground fast or easily. Stay locked underground or inside a heavy Long Distance ship for a couple of days is usually enough to escape the predator. Those caught on open areas have no chance.