Test blocks are a new type of unused operator blocks that were recently added to Minecraft 25w03a snapshot. They will soon be a part of the title with its upcoming drop.

If you want to get a mount so you can explore the Minecraft world from above, here's how to obtain and use the Dried Ghast block.

The latest is Snapshot 20w48a, which adds the fancy new dripstone block to Minecraft: Java Edition. This allows for the creation of stalagmites and stalactites in Minecraft's caves.