The Zoa or 'Ophanim' has a class called the Opanniel. They are described as mind blowingly awesome creatures having 16 faces, 100 wings, 2191 eyes on each of it's 4 sides, totalling 8766 eyes (one for each hour in a year). Only the Patriach Enoch wrote about them, as no human form could look upon one without being consumed instantly. It would take 2500 years to traverse it's length by foot (200 000 miles tall) and nothing can calculate the amplitude of its power except the King of Kings, YHWH himself.
Again, the Zoa are said to have 72 huge saphire stones in their garments, and one giant emerald on each crown. Their countenances are as brilliant as the sun, and dwell in unapproachable pavilions of light, and the brilliance of YHWH's Shakinah Glory is upon them (see Rev 4:6)
Opposite the throne of glory are creatures called 'The Watchers'. They are the ministers of heaven, more noble and greater than any of the angels, and will be and are responsable for ministering judgment on earth (see Isa 13). Each of their names are written with a pen of fire upon each of their crowns, as sparks and lightenings stream out from them. A river of holy flame flows among them, and ignites the stones of fire that blaze around God's holy presence.