Lava, like water, is a fluid. It can be found in Volcana, at Olmec's Lair, at the bottom of the third level in Tide Pool, and in Neo Babylon (might appear in other locations). It flows downwards and seeks its own level, just like water. There are a few differences, however. If the player touches lava, they will die, therefore, they cannot swim in it. However, the player can still whip lava like they can whip water. If the player is riding a mount and falls into lava, the mount will die and the player will automatically jump off the mount.
Like water, lava will disappear if it touches the exit door, and will not disappear if it touches the door at the start of the level or a door that leads into a "background room" (uncertain about term). Lava will also kill anything that falls into it, with the exception of Lavamanders. Magmars spawn and jump out of lava from time to time as well. Most items that fall into lava do not seem to be destroyed, such as Idols or the Golden Key (needs checking). When explosives come into contact with lava, they will explode. When the bottom of ropes come into contact with lava, the will burn from the bottom up. Lava will also emit light.