Changelings. With their shapeshifting abilities, they could replace your closest friends without you suspecting a thing. With their reliance on emotions to survive, they could be leeching on your mirth at this very moment. With their queen’s fierce nature, they could pose the biggest threat to Equestria yet…

That is, if they didn’t just sleep all day.

Cover image by equestria-prevails.
And yes, the title is a tangential reference to Mendacity. I tried.