You already have it.
* puts it on King's head *
See?
So, apparently Final Fantasy Crystal Chronicles Ring of Fates has a boss on Kilanda Isle that can be controlled, if its rider is knocked off...
Very pictured: Majora getting killed.
That reminds me: In Mario & Luigi: Dream Team (Bros), during the fight with Bowser Jr, you can take control of his Koopa Clown Car and then start throwing stuff at him. It's actually really fun and you also get your Bros Attacks back (which he steals from you).