That's what the TV show gets for pronouncing it "Wessen". In my dictionary (Cassell's), "creature" is not the primary definition of Wesen. It lists meanings in clusters: reality, substance, essence; being, creature, living thing, organism; state, condition; nature, character, property, intrinsic virtue; conduct, demeanour, air, way, bearing. My sense is more toward the essence of the thing, one's nature/character, so in that sense, it's 'creature,' inclusive of all living beings. But hey, it's German so the meaning comes from modifiers, and thus the definition of Wesen takes up almost a quarter of the page -- notably with no focus on what we would call a "Creature". "Das höchste Wesen," is the Supreme Being, not creature.