Praise be to Allah.
The question is composed of two parts.
1 – Do the jinn appear in human form?
2 – Do the jinn have a real form?
With regard to the first question, it may be said:
Firstly: it should be noted that the basic principle concerning the jinn is that they are concealed from mankind, hence they are called jinn, because the Arabic root janna refers to a single original meaning which is to cover and conceal, as Ibn Faris said in Maqayis al-Lughah. The jinn are so called because they are concealed from mankind, and the fetus is called janeen in Arabic because he is concealed in his mother’s womb, and a garden is called jannah because it is concealed by trees, and an insane person is called majnoon because his mind is covered, and so on in all derivations from this root.
Allah has told us of this when He said (interpretation of the meaning):
“O Children of Adam! Let not Shaytan (Satan) deceive you, as he got your parents [Adam and Hawwa] out of Paradise, stripping them of their raiments, to show them their private parts. Verily, he and Qabiluhu (his soldiers from the jinn or his tribe) see you from where you cannot see them.” [7:27]
Secondly: Can they appear in human form?
The answer to this is that it is proven in the sunnah (prophetic teachings) and from real life that the jinn appear in different forms, such as the forms of people and animals, etc. Among the clearest evidence of that from the sunnah is the story narrated by al-Bukhari from Abu Hurayrah (may Allah be pleased with him) who said: The Messenger of Allah (peace and blessings of Allah be upon him) put me in charge of guarding the zakah (poor-due) of Ramadhan. Someone came to me and started scooping up some of the food, and I said, “By Allah, I will take you to the Messenger of Allah (peace and blessings of Allah be upon him).” He complained of being in need and having dependents, so Abu Hurayrah (may Allah be pleased with him) took pity on him and let him go. This happened three times, and on the third occasion, Abu Hurayrah (may Allah be pleased with him) said: “I will take you to the Messenger of Allah. This is the third time and each time you say that you will not come back, then you come back.” He said, “Let me go and I will teach you something by means of which Allah will benefit you.” I said: “What is it?” He said: “When you go to bed, recite Ayat al-Kursi, ‘Allah! La ilaha illa Huwa (none has the right to be worshipped but He), Al-Hayyul-Qayyum (the Ever Living, the One Who sustains and protects all that exists)…’ [2:255] until you complete the verse, then you will always have a protector from Allah, and no devil will come near you until morning comes. So I let him go, and the next morning I told the Messenger of Allah (peace and blessings of Allah be upon him) what had happened. The Messenger of Allah (peace and blessings of Allah be upon him) said: “He told you the truth, although he is a liar. Do you know who you have been speaking to for three nights, O Abu Hurayrah?” He said: “No.” He said: “That was a devil (a shaytan).”
Al-Hafiz ibn Hajar said in al-Fath: This hadeeth (narration) teaches us a number of things… that one of the characteristics of the shaytan is lying, and that he may appear in various forms that may be seen, and that the words of Allah, “Verily, he and Qabiluhu (his soldiers from the jinn or his tribe) see you from where you cannot see them” [7:27], apply to when he is in the form with which he was created.
It was narrated that the shaytan appeared to Quraysh in the form of Suraqah ibn Malik ibn Ju’sham and encouraged them to fight the Prophet (peace and blessings of Allah be upon him). This happened during the battle of Badr. Ibn Jarir al-Tabari narrated in his Tafsir that ‘Urwah ibn al-Zubayr said:
When Quraysh decided to march, mention was made of what was between them and Bani Bakr – i.e., war – and that almost made them change their minds. Then Iblis appeared to them in the form of Suraqah ibn Ju’sham al-Madlaji, who was one of the nobles of Banu Kinanah, and said: “I will protect you against Kinanah so that Kinanah will not be able to do you any harm.” So they went ahead with their plan. This was also quoted by Ibn Kathir in al-Bidayah wa’l-Nihayah.
In Saheeh Muslim it is narrated that Abu Sa’eed al-Khudri (may Allah be pleased with him) said: I heard the Messenger of Allah (peace and blessings of Allah be upon him) say: “In Madinah there is a group of the jinn who have become Muslim, so whoever sees any of these creatures let him give it a warning three times, then if it appears after that he may kill it, for it is a devil.”
The word translated as “creatures” here refers to kinds of snakes that appear in houses; they are not to be killed until they have been given a warning three times, because they may be jinn. See Ghareeb al-Hadeeth by Ibn al-Atheer.
Al-Nawawi said: What this means is that if they do not disappear after being warned, then they are not the kind of creatures that inhabit houses and they are not among the jinn who have become Muslim, rather that is a devil so there is no sin on you if you kill it and Allah will never give the shaytan a way to prevail over you by taking revenge, unlike the creatures (snakes) and jinn who have become Muslim. And Allah knows best. Sharh Muslim.
There have been many such incidents. Shaykh al-Islam (Ibn Taymiyah) said: The jinn may appear in human and animal form, so they may appear as snakes and scorpions etc, or in the form of camels, cattle, sheep, horses, mules and donkeys, or in the form of birds, or in the form of humans, as the shaytan came to Quraysh in the form of Suraqah ibn Malik ibn Ju’sham when they wanted to set out for Badr.
Thirdly: The jinn have led many people astray by appearing in the forms of awliya’ (“saints”) and righteous people etc. Shaykh al-Islam said: The shaytan often appears in the form of the person who is being called upon and asked for help, if he is dead or sometimes if he is alive, without the person who called upon him realizing it. Indeed the shaytan may appear in his form and the misguided mushrik (pagan) who is seeking that person’s help may think that the person himself has responded to him when in fact it is the shaytan. This also happens to the kuffar (non-Muslims) who seek the help of those of whom they think well, whether they are dead or alive, such as the Christians who seek the help of George or others of their saints, and it happens to those so-called Muslims who commit shirk (polytheism) and follow misguidance by seeking the help of those who are dead or absent. The shaytan appears to them in the form of the one upon whom they call, without them realizing it… More than one person has told me that they sought my help, and each of them told me a different story. I told each one of them that I did not answer any one of them and I did not know that they were seeking my help. It was said that this was an angel, but I said: Angels do not help mushriks, rather that was a devil who wanted to misguide him.
One of the greatest ways in which a Muslim may seek help against the devils is to “fortify” himself with adhkar (words of remembrance) and reciting Ayat al-Kursiy, as stated in the hadeeth of Abu Hurayrah (may Allah be pleased with him) quoted above.
With regard to the second part of the question, which is whether the jinn have a true form:
With regard to this matter of photographs of the jinn, which have fascinated many people and become widespread on some websites, it is not possible to verify the authenticity of what is in these websites, especially nowadays when people are highly skilled in producing all kinds of deceptive pictures. Moreover, researching such matters brings no spiritual or worldly benefit and serves no purpose. It is better to occupy oneself with things that will bring spiritual or worldly benefit such as reading and understanding what is in the Quran and the saheeh sunnah (authentic prophetic teachings), and what a person needs to know and do of correct belief and worship, and the proper attitude and etiquette which the Muslim should develop, and so on. It should also be noted that publishing pictures of animate beings is haram (impermissible) according to sharee’ah (Islamic law) as is stated in the texts. See questions no. 13633, 10668 and 7918.
We ask Allah to protect you and raise you in status and forgive your sins and bless you with knowledge and good deeds, for He is the Best One to be asked.
May Allah send blessings and peace upon our Prophet Muhammad and his family and companions.
And Allah knows best.