The Messenger of Allah ﷺ said that Allah said, "Who is more unjust than one who sets out to create as I create? Let them create a gnat, or let them create an ant."
وبالإسناد قال رسول الله ﷺ يعني قال الله عز وجل ومن أظلم ممن خلق كخلقي فليخلقوا بعوضة أو ليخلقوا ذرة
Its chain of transmission is sahih. Bukhari narrated it in the Book of Dress, chapter on the destruction of images, 7/215, and in the Book of Tawhid, chapter on "Allah created you and what you do," and Muslim narrated it in 3/1671, number 2111, in the Book of Dress, chapter on the prohibition of depicting images of animals.