The closest the Bible comes to describing what Satan and the demons look like is in 2 Corinthians 11:14, “And no marvel; for Satan himself is transformed into an angel of light.”The surrounding verses refer to Satan’s human servants disguising themselves as “apostles of Christ” and “servants of righteousness.” In context, these descriptions are referring to false teachers. But the principle applies to demons as well.
One problem — and it’s a big one — with trying to describe what Satan and demons look like is that they are spirits. Spirits are, by definition, non-physical, and it is impossible to assign physical features to a non-physical entity. As spirit beings, demons do not have noses, eyes, hands, feet, tails, or anything else that we might look for in drafting a description. That’s one reason why the Bible never describes Satan’s appearance. The “angel of light” description in 2 Corinthians 11:14 is not meant as a sketch of his appearance; rather, it means to emphasize the deceitful nature of Satan. The devil wants us to believe he is truth when in reality he is falsehood.
What demons do, is to imbue man with imagery, through dreams, visions and suggestions. Man takes these suggestions and creates an image of a demon, by drawings and other means of depictions. Once man tangibly creates these images, in drawings, sculptures, movies, games etc; a demon can take on these appearances as aberrations. The walking dead, demonic imagery as in the exorcist films etc… whatever we can conjure up in our minds as influence by demons the demon can use this fear and imagery in a physical form be it mentally, visually or in a tangible physical appearance. Keep in mind, Angels appear to man as men, and we may never know it.
“Be not forgetful to entertain strangers: for thereby some have entertained angels unawares.” Hebrews 13:2 (example: Judges 13:9–16)
Now that we’ve established that Satan is an angel, a spirit being, having no physical likeness that can be grasped by our senses, we can do some surmising. Should Satan decide to make a physical appearance — if he manifested himself to us visibly — he would do so in a deceptive manner.
The common, pop culture portrayal of Satan as a scary-looking, goat-like beast with horns is not found in the Bible. Prior to his rebellion against God, Satan was a beautiful, glorious being (Ezekiel 28:12–15). What Satan “looks like” now is a mystery. Based on 2 Corinthians 11:14, we can know one thing for certain: Satan deceives people into thinking he is an angel of light. For Satan to reveal himself as the evil, murderous being that he is, would be counterproductive. Most people would not follow the hateful, malicious maniac of conventional portrayals. Just as sin often looks attractive at first — only later revealing that it leads to death — so Satan would seek to deceive us by appearing as something other than evil.
The same is likely true of the demons. What do demons look like? No one in the Bible ever saw one outside of Micaiah’s and John’s divine visions; Micaiah did not provide visual details, and John, using apocalyptic symbolism, wrote of spirits “like frogs” (1 Kings 22:21–22 and Revelation 16:13). If demons were to take visible form, they would choose whatever would further their deception. As fallen angels, the demons are intelligent and powerful beings. And they are led by perhaps the one of the most powerful created beings (Jude 1:9), Satan, whose example they follow. The demons appearing as the evil beings they really are would hinder their mission of deception and temptation.
If they did appear, they would put on a masquerade. Deception always wears a mask. Satan and the demons attempt to portray themselves as servants, guides, and “light” for people. But, make no mistake, “the thief comes only to steal and kill and destroy” (John 10:10).
No matter what Satan would like us to think about himself, we know the truth: “Be sober, be vigilant; because your adversary the devil, as a roaring lion, walketh about, seeking whom he may devour:” 1 Peter 5:8
The reality of Satan is something that man will tangibly see at the judgment, it should be considered in the midst of all the deception man experiences until then.
“How art thou fallen from heaven, O Lucifer, son of the morning! how art thou cut down to the ground, which didst weaken the nations! For thou hast said in thine heart, I will ascend into heaven, I will exalt my throne above the stars of God: I will sit also upon the mount of the congregation, in the sides of the north: I will ascend above the heights of the clouds; I will be like the most High. Yet thou shalt be brought down to hell, to the sides of the pit. They that see thee shall narrowly look upon thee, and consider thee, saying, Is this the man that made the earth to tremble, that did shake kingdoms” Isaiah 14:12–16