I was wondering, it is said that the people of Paradise will have curly hair in terms of their most beautiful and perfect form. However, it is said that the Dajjaal (the Antichrist), that most evil figure, has curly hair as well. Why does such a despicable being have a beauty trait of the residents of Paradise?

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. 

The answer to this question is that having curly hair is used for praise while it is also used for dispraise; Al-‘Ayni said in ‘Umdat-ul-Qaari’, “We have mentioned that having curly hair is used for dispraise and praise, according to usage; in regard to the description of ‘Eesa (Jesus), it is praise, and in regard to the description of the Antichrist, it is dispraise.” 

Having curly hair has been interpreted in regard to the Antichrist by what Ibn Abd Al-Barr stated in At-Tamheed, as he said, "The saying: 'curly' in the description of the Antichrist is broken twisted hair that is never straight, like the hair of Abyssinians.”

However, we did not come across a scholar who interpreted the meaning of curly hair for the people of Paradise; but it is a description of praise, without a doubt. This description was mentioned in the hadeeth narrated by Ahmad in his Musnad from Abu Hurayrah, may Allah be pleased with him, who related that the Prophet said, “The people of Paradise will enter (Paradise) beardless, fair, with curly hair, and kohl on their eyes...”

Allah knows best.