WotC has sent along a Derro-themed package today. This is a page from Out of the Abyss (the upcoming adventure, September 15th), plus an additional piece of Derro-tastic art. Derro, as you may know, first showed up in 1982's The Lost Caverns of Tsojcanth. Degenerate dwarves, they are evil and sneaky, and often feature powerful magic-wielding savants in their midst. Not only that, though - this page also shows an index of all the new NPCs and monsters in the adventure, sorted by Challenge Rating!
For my previous coverage of Out of the Abyss, including lots of other previews, click right here!