The most grievous torfnent for the people on the Day of Resurrection would be for those who try to imitate Allah in the act of creation. (Using translation from Muslim 2107f)
دَخَلَ النَّبِيُّ ﷺ وَأَنَا مُسْتَتِرَةٌ بِقِرَامٍ فِيهِ صُورَةٌ فَهَتَكَهُ ثُمَّ قَالَ إِنَّ أَشَدَّ النَّاسِ عَذَابًا يَوْمَ الْقِيَامَةِ الَّذِينَ يُشَبِّهُونَ بِخَلْقِ اللهِ ﷻ