I agree but I would like to add a few things. The reason that satan was pictured as the red skinned horned creature is because this is how he is described in Revelation.

Revelation 12:3 Then another sign appeared in heaven: an enormous red dragon with seven heads and ten horns and seven crowns on its heads.

The dragon is satan.

Revelation 20:2 He seized the dragon, that ancient serpent, who is the devil, or Satan, and bound him for a thousand years.

I believe that satan and the demons can be in many forms. Angels can manifest whether they are good angels or evil angels. They can also be powers that attempt to cause us problems or can inhabit people. People can be demonized. I have dealt with each type.

Hebrews 13:2 Do not forget to show hospitality to strangers, for by so doing some people have shown hospitality to angels without knowing it.

Genesis 19:1 The two angels arrived at Sodom in the evening, and Lot was sitting in the gateway of the city. When he saw them, he got up to meet them and bowed down with his face to the ground.

2 Corinthians 11:14 And no wonder, for Satan himself masquerades as an angel of light.

Ephesians 6:12 For our struggle is not against flesh and blood, but against the rulers, against the authorities, against the powers of this dark world and against the spiritual forces of evil in the heavenly realms.

Matthew 10:8 Heal the sick, raise the dead, cleanse those who have leprosy, drive out demons. Freely you have received; freely give.

It is important to know to test the spirits to see if they are of God or satan because they sometimes try to lead us in wrong directions with very small steps. Satan and his demons can be very tricky.

1 John 4:1 Dear friends, do not believe every spirit, but test the spirits to see whether they are from God, because many false prophets have gone out into the world.

Then, we can rebuke them in the name of Jesus.

Jude 1:9 But even the archangel Michael, when he was disputing with the devil about the body of Moses, did not himself dare to condemn him for slander but said, "The Lord rebuke you!"

Matthew 10:8 Heal the sick, raise the dead, cleanse those who have leprosy, drive out demons. Freely you have received; freely give.

I always tell my brothers and sisters in Christ to ask Jesus to come and stand next to them when they face evil. He will. I always do this. Then, He completely changes the situation for the better. The power of God is amazing.