Megalophobia

r/megalophobia is a my new favorite subreddit, specializing in things that are very big and therefore very, very scary. Postings range from Lovecraftian monsters looming in the mist to zoom-out animations impressing upon the viewer the insignificance of Planet Earth and all human concerns. Currently popular are disturbing photoshops of large comets looming over the major cities they are about to destroy.
Above is 'War Machines,' by Simon Stålenhag (previously).