Which prophet made iron horns and told Ahab he would gore the Arameans?

Answer: Zedekiah son of Chenaanah

Zedekiah son of Chenaanah made iron horns and declared Ahab would gore the Arameans; Micaiah later foretold defeat.

“Now Zedekiah son of Chenaanah had made for himself iron horns and declared, “This is what the LORD says: ‘With these you shall gore the Arameans until they are finished off.’””— 1 Kings 22:11 (BSB)