As Framed - I'm not sure it's possible. The reason I say that is you mention it has a Muscle and Skeletal system - both of which are living systems and both need nutrients (okay, we get that from the Planet core) but more importantly - Will need some form of Oxygen (how can we breathe without a mouth and osmosis of Oxygen through a body that size is pushing it) and it will produce some form of waste product that will need to go somewhere.
Let's assume for the moment that it has a super-absorbent skin layer that secretes something that allows it to 'digest' minerals in the earth and absorb them into the skin - say Iron. So now instead of having a traditional Skeletal system, our Moose has Iron for bones, literally. The Skeleton being close to the Skin allows for absorption and maybe not a full circulatory system, but a capillary type system between the Skin and the Iron bones, the Skin also absorbs ambient moisture to allow for the transmission of necessary minerals in this capillary system.
Why would such a creature evolve? Well, without a Circulatory system, it's remarkably resilient. It can't bleed out, it has no heart or lungs that can be punctured/destroyed - and it's Iron bones make it rather strong.
For muscles - again, we are going to think outside the box here for a moment - we have Metal Bones.
Bi-Metallic strips bend. We could have something where the energy from the core causes localized build-up of heat that bends the limbs, generating muscle-like motion and force - they work in antagonistic pairs, like real muscles. And as a bonus - they don't need Oxygen or have any nasty waste products that need to be transported away.
That's the best I got.