Java Edition 16w21a

16w21a is the second snapshot for Java Edition 1.10, released on May 25, 2016, which made minor changes to the behavior of blocks and items and fixed bugs.

Command format

 * NBT Tags
 * Allows mobs to use elytra when they fall.
 * Mobs lose their ability to fly after touching the ground.
 * Mobs lose their ability to fly after touching the ground.

Blocks

 * Bone blocks
 * No longer transparent.


 * Dispensers
 * Can now equip shields onto entities.


 * Rails (all types)
 * Bounding box for ascending rails is a full block (formerly only $5/32$ of a block tall).


 * Structure block
 * No longer emit light.
 * Added "Structure Integrity and Seed" to load mode (NBT tags  and   respectively).

Items

 * Chorus fruit
 * Can now teleport riders from their mounts.


 * Ender pearls
 * Can now teleport riders from their mounts.


 * Fishing rod
 * Can now pull items to the player.

Mobs

 * Wolves
 * No longer despawn.

World generation

 * End portals
 * Now replace any blocks inside the portal frame ring when activating.


 * Villages
 * Blacksmiths now generate with cobblestone in all biomes (rather than acacia logs in savannas and sandstone in deserts).

Command format

 * NBT tags
 * and  tags are now fully removed, replaced by the   first added in 16w20a.

General

 * Particles
 * now can be summoned, making use of the  argument like   and several other particles do.
 * Example: will summon a particle matching the color of lava (block ID 10).

Video
Video made by slicedlime:

Trivia

 * 16w21a was previously removed from the launcher for some time, but was added back in September 2018.