Possible Clues:

• 'Daddy' rapper
• Korean rapper with the 2013 hit "Gentleman"
• Rapper with the 2014 hit 'Hangover'
• ___.D. (degree for some therapists)
• Korean rapper who had a 2012 megahit
• —OPs (CIA tactics)
• Mononymous K-pop star
• 'Gangnam Style' artist
• Rapper whose “Hangover” featured Snoop Dogg
• 'Gangnam Style' hitmaker