Minecraft wiki entry for Development_versions, associated text: Generates in the Deep Dark biome.
Has an animated texture.
Drops only experience when broken without Silk Touch.
When wool blocks are placed on a sculk block, it will let nearby sculk sensors know, preventing that vibration from being occluded.
Sculk blocks grow when a mob dies near a sculk catalyst.
If sculk shriekers activate three times, a warden may emerge from the sculk blocks.