ok, here& #39;s a question for #dnd5e rules buffs

the rules sometimes use the term & #39;living creature& #39; but I& #39;m not sure how that is actually defined because for things like golems, devils or animated tables this is weird territory

is it creatures with a soul, because that& #39;s one thing, and what about creatures that are pure soul, or have no soul

what about revenants. they are undead but canonically have their souls

or is it just sentient beings, because at what point is the intelligence cut-off

people asking for examples:

a bag of devouring (DMG) states "When part of a living creature is placed in the bag"

an ash zombie (LMOP) says "any living creature within 5 feet of the zombie"

galder& #39;s speedy courier (LLOK) says "You can then name a living creature"

also if you could come at me with citations for these opinions that& #39;d be ace, I& #39;m looking for clarity here