Lava is one of the many Liquids that exist in Creativerse. It is yellow with orange blotches and is able to flow downwards as well as to spread sideways.
However, liquid Lava hardens very easily if not surrounded by hot blocks like Hardened Lava or heated up by heat-emitting objects. Liquid Lava will stay liquid on the Lava layer where it can also be found in abundance, since the base temperature of this underground layer is high.
Lava requires a Diamond Mining Cell to be foraged. Even using a Lumite Mining Cell, which is currently the best Power Cell in the game, will still lose durability considerably when scooping up liquid Lava.
Since update R62 liquid Lava can be removed with Super Excavator.
How to obtain
As there are no volcanos in the game (yet), Liquid Lava can usually only be found on the Lava layer underground on every Creativerse gameworld.
Hardened Lava itself cannot be produced by throwing Fire Bombs against blocks of Igneous Rock any longer though, while in return Hardened Lava is able to cool down in cool environments or when cooled down by players (like with Freeze Bombs) and will then transform into Igneous Rock.
On the Lava layer, Liquid Lava often forms lakes and sometimes low cataracts, but no vast oceans.
Occasionally, Liquid Lava can even drop down through holes or caverns here and there as far as into the Corruption layer.
Heat and burning
Liquid Lava can be deadly for player-characters and most Creatures (like Keepas for example) because it inflicts fire damage immediately when being touched, no matter how full or empty the heat meter (scale) is.
The heat meater will show up when being and staying close to hot blocks or liquid Lava itself. As soon as the heat scale has fully turned red, the affected player character will start to burn and be dealt fire damage over time quickly.
However, Creatures and player-characters won't die immediately even when falling into Lava. Instead, touching liquid Lava will also set characters and Creatures (except for Hot Feet and all Pets) on fire, which will deal burning damage over time that will last for about 3 seconds longer after stepping away from the Lava.
Cooking with Lava
Liquid Lava is useful for cooking certain kinds of Food in the Cooking Station, like Blazing Soups, Blazing Breads, Blazing Sandwiches and Blazing Pies that will give player characters some resistance up to complete immunity to fire damage or will even transform the damage over time that is inflicted by burning into healing over time.
You will not need to unlock any specific recipes other than the basic ones (only 4 currently exist: Soup, Bread, Sandwich, Pie) for this, as depending on the ingredients used, different types of Food can be created with only these 4 recipes.
Preventing burning damage
Liquid Lava will not cause any damage when being foraged, being carried in the inventory or any quickslots, and it will also neither burn anything nor change when being stored in containers.
Fire Resistance Potions will not provide immunity to fire damage inflicted by lava, they will only reduce the fire damage over time to half of it's intensity, however it also seems that player characters burn less long.
These potions mainly negate the heat scale/meter that shows up and is starting to fill itself with red color when the environment is very hot.
The best means to prevent burning damage is to eat Blazing Pie or Blazing Sandwiches, since they will turn fire damage into healing. While these types of Food will not prevent the heat meter from rising, even a fully red heat scale will not deal any damage to player characters.
Blazing Soup and Blazing Bread will only reduce fire damage taken, no matter if by a full heat gauge, falling into liquid Lava or being attacked by either a Hot Foot or Warmworm (or even a Wraithworm like W'urm).
Liquid Lava can harden and such turn into Hardened Lava (which makes good Fuel) when players place this liquid into cooler biomes, or by pouring Water or Mineral Water on liquid Lava or upon throwing Freeze Bombs at it.
Beware: Hardened Lava blocks can make Hot Feet spawn if not lit up (with lamps) additionally, and these aggressive Creatures can swim in liquid Lava unfazed - however these sunlight-sensitive underground Creatures will start to burn and then perish if being hit by sunlight.
It is actually possible (but unconfirmed yet) that liquid Lava itself is able to make Hot Feet spawn too.
Lava can burn vegetal materials and objects
Placing flammable blocks, materials and objects like wooden furniture (for example Wood Doors) or wooden building-blocks (like Wood Walls, Wood Floors, Red Wood Walls and others) next to or into liquid Lava will immediately set them on fire that will then completely consume them.
The same goes for many other flammable materials and objects; all types of Wood blocks from Cragwood to Corrupted Wood (even though the latter burns only reluctantly), all types of tree Leaves, all Flowers, Tallgrass, Shrubs and other plants, but also Wood Tables, Wood Chairs, Wood Windows and the like.
To learn more about this, please refer to the article Fire.
Beware of spreading fire when using liquid Lava!
Also placing liquid Lava next to flammable blocks/items will have the same effect (until the Lava turns into Hardened Lava blocks) and can then spread fire onto other flammable blocks nearby, so a whole wooden building or forest can burn down by that in time if you try this on the surface.
Fire cannot be extinguished by using liquids, but it can be stopped from spreading by claiming the area and making sure that the claim (advanced) option "fire sim enabled" is disabled. Currently fire will not spread and Fire Bombs will have no effect on player claims by default, but this option can be toggled by the claim owners.
It is also possible for owners of the gameworld (F2P players too) to toggle the spreading of fire on a whole gameworld in the basic world options ("edit world" and "disable fire spread"). Another option to stop fire from spreading would be to create forest aisles/swaths wide enough so that the flames cannot leap over.