Magma
From The Blockheads Wiki
Lava appears when your Blockhead reaches the center of the world.
Your Blockhead begins to smoke as it nears lava. This is to warn you that it will be injured if it gets too close. That said, Blockheads can walk on lava.
Water can be poured on lava and appears to cool it because the color of the lava covered in water goes from red to orange.
