Ezekiel 1:10-14

Regarding the form and appearance of their faces: they [each] had the face of a man [in front], and each had the face of a lion on the right side, and the face of an ox on the left side; all four also had the face of an eagle [at the back of their heads]. [Rev 4:7] Such were their faces. Their wings were stretched out upward; two [wings] of each one were touching another [the wings of the beings on either side of it], and [the remaining] two [wings of each being] were covering their bodies. And each went straight forward; wherever the spirit was about to go, they would go, without turning as they went. Among the living beings there was something that looked like burning coals of fire, like torches moving back and forth among the living beings. The fire was bright, and lightning was flashing from the fire. And the living beings moved rapidly back and forth like flashes of lightning.