Recently you have seen my fursona into this new form but you didn't many information about it Well here the are: this is the form that David acquire after the invocation of Mahal, the Elemental Guardian of Earth. I will make soon a journal about the elemental guardians for explain better who they are; anyway on this other pic there is a brief explanation
http://www.furaffinity.net/view/5543621/
http://www.furaffinity.net/view/5543842/

GENERAL OVERVIEW:
Mahal is the ancient and powerful spirit who is the Earth guardian and master. In the ancient time he was sometimes invocated by wizard whoa sked his help for building ancient city and monumnets, a task that for the spoirit was a mere child play
The simbol that appears on his belly is the alchemical symbol of earth.

PERSONALITY:
Mahal personality is actually confusing for wizards that summon him for the first time. He usually present himself as a childish and naive entity (a personality very similar to that of Goku from Dragonball as a child) but this actually only a test of the spirit for seeing who is the one who has summoned him. After that he is sure of the wizard intentions Mahl reveal his true nature as a powerful,wise, strong yet kind spirit.

POWERS:

-super-strenght : Mahal’s strength has magical origin so he is actually much stronger than individuals with powers derived from mutation and/or technology
-super-toughness and endurance: he is able to going easily through situations that could kill a normal individual instantly. Stuff like bombs and even missiles explosions do not create him absolutely no harm. He also has a great resistance toward extreme high or low temperatures.
-healing factor: even if by some means he is hurt Mahal is able to heal very fast, thanks to his magical abilities
- he can alter his personal mono-directional gravity field beneath himself to make himself virtually immovable as long as he is in contact with the ground
- he has the ability to shift tectonic plates to cause earthquakes and create chasms, and levitate large land masses miles into the air. He also has a limited control over volcanic eruptions.
- mental ability to manipulate the molecules of rock and earth: Mahal can create almost any kind of object by mentally manipulating the molecules of various materials that are present in the earth.
He can also create Golem-like creatures of great strength who obey to his will.
-growing abilities: Mahal can grow to giant size. Apparently this powers doesn’t seem to have a real limit. This power also influence Mahal’s others powers: the more he grows the more his other powers become more powerful
-body manipulation: Mahal can alter the molecular structure of his body by mimicking the properties of various substances or materials. For example he can incorporate metal like molecules into his body for bolster his toughness. Or in alternative he can turn his body into a clay like substance and this allows Mahal to gain additional powers like shape shifting, the ability to squeeze through tiny holes or fissures

WEAKNESSES:
If Mahal is somewhat unable to have a physical contact with earth he is not able to enhance his powers: however he does still maintain high strength and toughness.
Also Mahal has a great sense of honor: he will never use his powers to cheat in a fight. So when he fights against an opponent he usually refuses to grow more powerful than his opponent but maintain his power at the same level of his opponent (unless of course he had a good reason for stopping his opponent quickly, like if there was an innocent in life danger).
This characteristic may be a weakness in some cases.

INSPIRATION:
I was basically inspired these Marvel’s characthers:
-The Juggernaut
-Fred J Dukes aka The Blob
-Terrax, one of Galactus’s aralds