Assalaamu alaykum. Are the Hoors (maidens of Paradise) a completely new creature?

All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger.

We do not know exactly what you mean by ‘a new creature’, but what we can say is that the Hoor Al-`Een are one of the creatures of Allah whom Allah created to be the wives of the people of Paradise. Allah says (what means): {And [for them are] fair women with large [beautiful] eyes. The likenesses of pearls well-protected, as reward for what they used to do.} [Quran 56: 22-24]

It should be noted that just as the Hoor Al-`Een are the wives of the people of Paradise, similarly, the women who are predestined to enter Paradise from among the women of this world will be wives of the people of Paradise, as Allah says (what means): {Indeed, We have produced the women of Paradise in a [new] creation. And made them virgins. Devoted [to their husbands] and of equal age. For the companions of the right.} [Quran 56:36-38]

Ibn Katheer said in his Tafseer (exegesis), “Meaning, in the other life, after they became old and previously married with Ramas (i.e. white secretion of the eye) in this life, they were brought back as virgins; youthful, delightfully passionate with their husbands, beautiful, kind, and cheerful.”

The other evidence that proves that the verses mean the wives of the children of Aadam [i.e. the women of this worldly life], is what At-Tirmithi reported in Ash-Shamaa’il, and Al-Albaani classified its chain of narrators as hasan (good); that an old woman came to the Prophet and said, “O Messenger of Allah, ask Allah to grant me entrance into Paradise.” The Prophet replied, “O Mother of so-and-so, an old woman cannot enter Paradise.” The woman started crying and began to leave. The Prophet said, “Tell her that she will not enter it as an old woman, but Allah will make all the women of Paradise young and virgins. Allah says (what means):  {Indeed, We have produced the women of Paradise in a [new] creation. And made them virgins. Devoted [to their husbands] and of equal age.}”

Allah knows best.