Ezekiel 1:10-11

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.