This is the living creature that I saw

But though Ezekiel introduces them as four living ones and four wheels in ch. i. 5,16, in referring to them in ch. x. 15, he speaks of them as one, saying, "this is hachaiyah, THE LIVING ONE." In other words, the individuals of whom this Spirit manifestation is composed are, in the aggregate, what the voice issuing from their midst proclaims without intermission day and night, namely, the thrice or superlatively holy YAHWEH, the Omnipotent Deity, who was, and who is, and who is coming (Apoc. iv. 8). These are the ONE BODY, nearly all the atoms of which are now in death, "sleeping in the dust." But, speaking of them as they are now in reference to its future, the Spirit styles them "My DEAD BODY, and says "they shall arise," and, in view of the resurrection, exclaims, "Awake and sing, ye that dwell in the dust." When they come forth from the dust they are no longer the Spirit’s Dead Body, but they become the Spirit’s Living One, and can then say, "I am the First and the Last, and the Living One: and I was dead, and behold I am living for the Aions of the Aions, the Amen." Jesus is the visible Head of these. Without Him the Living One would be incomplete (Isa. xxvi. 19; Apoc. i. 18).

Ezekiel clearly indicates what was represented by the four living ones and their wheels in ch. i. 24. He says, "The noise of their wings was like the noise of great waters, as the voice of shaddai, MIGHTY ONES, the voice of speech, as the noise of a host." This was equivalent to saying that their wings represented "great waters," which represented "Mighty Ones," who gave utterance to their will and purpose, and that there was a multitude of them.