Possible Clues:

• He's not likely to be a good boy!
• Mr___ (most-subscribed-to YouTuber)
• Griffin or manticore, e.g
• 'X-Men' character with blue fur
• Be a really good person -- or cruel and brutal one!
• Griffin, for example
• Blue member of the X-Men
• 24-Across' love, with "the"
• 24-Across' love, with 'the'
• Pound locks up special animal