Qur'an Quiz No. 4
I am mentioned in the Noble Quran
I swallowed by that which has no mouth
I used to be famous around town, envied by many
But now I've became a lesson for the proud and arrogant
Who am I?

Qaroon
He was a very wealthy man and very arrogant. He believed his riches and status was obtained solely through his own skills and knowledge and never attributed any of it to Allah.
He was envied by many people and warned by some but he did not take heed and as a result was swallowed by the earth.
28:76
۞ إِنَّ قَـٰرُونَ كَانَ مِن قَوْمِ مُوسَىٰ فَبَغَىٰ عَلَيْهِمْ ۖ وَءَاتَيْنَـٰهُ مِنَ ٱلْكُنُوزِ مَآ إِنَّ مَفَاتِحَهُۥ لَتَنُوٓأُ بِٱلْعُصْبَةِ أُو۟لِى ٱلْقُوَّةِ إِذْ قَالَ لَهُۥ قَوْمُهُۥ لَا تَفْرَحْ ۖ إِنَّ ٱللَّهَ لَا يُحِبُّ ٱلْفَرِحِينَ ٧٦
Indeed, Qārūn was from the people of Moses, but he tyrannized them. And We gave him of treasures whose keys would burden a band of strong men; thereupon his people said to him, "Do not exult. Indeed, Allāh does not like the exultant.
— Saheeh International
Qārūn was the cousin of Moses. Because of Qārūn’s close association with Pharaoh, he became very rich and started to behave arrogantly towards his own people. When he was asked repeatedly by Moses (ﷺ) to pay his alms-tax to help poor Israelites, Qārūn refused and eventually conspired with a prostitute to damage the reputation of Moses, but Moses was cleared of any wrongdoing.