Obsidian Spike

Obsidian spikes are structures found in the mantle. There are two types, a shorter and a taller version.

Generation
Obsidian spikes spawn only in the mantle in Byatis, in high numbers. They stick out of the surface.

Blocks
As the name suggests, obsidian spikes are made only out of obsidian.

Lore
Similar to basalt pillars in the nether, obsidian spikes are shock-cooled bursts of lava from below the surface, interacting instantly with the water. (That's not how obsidian is formed IRL, but this is Minecraft).