Jamieson, Fausset and Brown on Ezekiel 10:14

14. cherub--but in Eze 1:10 it is an ox. The chief of the four cherubic forms was not the ox, but man. Therefore "cherub" cannot be synonymous with "ox." Probably Ezekiel, standing in front of one of the cherubim (namely, that which handed the coals to the man in linen), saw of him, not merely the ox-form, but the whole fourfold form, and therefore calls him simply "cherub"; whereas of the other three, having only a side view, he specifies the form of each which met his eye [Fairbairn]. As to the likelihood of the lower animals sharing in "the restoration of all things," see Is 11:6; 65:25; Ro 8:20, 21; this accords with the animal forms combined with the human to typify redeemed man.