https://mojang.com/2016/09/minecraft-snapshot-16w39a-the-exploration-update/
As always there are many other neat additions in this update, and here is the intentionally noninformative change log:
Added cursed enchantments
Added the Observer block
Added escape portals in The End
Added the Shulker Shell and Shulker Box
Added exploration maps
Added the Woodland Mansion
Added Illagers, and the Vex
Added Llamas
New command: /locate
Removed Herobrine
Bugs fixed in 16w39a:
[Bug MC-58677] - GUI has inconsistent capitalization
[Bug MC-92139] - Too many tipped arrows in the “Combat” section of the creative inventory
[Bug MC-106077] - Missing sound files (largeblast1.ogg / largeblast_far1.ogg) because of CamelCase in 1.11.json
[Bug MC-107154] - Junk potion from fishing is uncraftable potion
[Bug MC-107165] - Brewing icon displays the incorrect color in Creative inventory tab
[Bug MC-107166] - Experience bottles produce pink particles.
[Bug MC-107170] - writeString method of PacketBuffer is not creating correct exception text
[Bug MC-107284] - disabling shields with axes doesn’t work
[Bug MC-107320] - Sort order of command autocomplete confusing
