Animus

Animus is stuff that moves.
Compared to the other parts of the soul, Animus is easy to touch and manipulate. Animus comes from the four elements (fire, earth, water, and air) permeating Scarterras. If a wizard conjures a fireball, cloud of mist, or really anything the wizard is calling upon ambient animus to power his spells.
A zombie or skeleton can stay active for a long time without feeding on the living because the spell that creates them because they passively siphon animus from the surrounding area.
If a magic user is using divination magic to detect and identify magic she is attuning her senses to disruption in Animus. If a magic user is magically paralyzing an opponent, he is temporarily locking a person’s animus. Is someone using telekinesis? That’s manipulating Animus.
Is it possible for a person to not have Animus? Yes. A living person with no Animus is petrified. A dead person with no Animus is a ghost or other incorporeal spirit.
Everything that moves in the physical plane has some animus. It’s pretty easy for living things to have animus, even slow growing plants have a tiny bit of Animus. If a rock is thrown, the rock doesn’t have Animus. Whoever threw the rock “loaned” the rock a bit of Animus.
Most permanent magical items are enchanted to slowly pick up Animus from the area around them. For a typical magical sword or shambling zombie that is enough.
Elementals have LOTS of Animus. If a mage wants to create a giant golem or some other artificial magical creature that moves with great strength, the most straightforward way to do this is to bind an elemental permanently. Some view this as unethical. Scarterrans and Scaraquans do not agree on whether elementals are properly alive especially the fanatics in P.E.T.E who are vehemently opposed to the magical exploitation of elementals.

The P.E.T.E. or People for the Ethical Treatment of Elementals is in joke among some of my friends.