Who was the man upon whom the Messenger of Allah, peace and blessings be upon him, invoked Allah to set one of His dogs upon him at the beginning of his call, and what was the reason for his supplication against him?

The Prophet, peace and blessings be upon him, invoked Allah against Utbah ibn Abi Lahab due to his harassment, mockery, and attacks against him. Allah answered the Prophet's supplication, and He set a lion upon Utbah, which crushed and tore him apart. This is Allah's punishment for anyone who belittles the Prophet, insults him, despises him, or diminishes his Sunnah.