w00t I did it! (Didn’t get the drop though)
For those wondering how to do it, Luigi must be at least level 9 or 10. (Higher then 10 is recommended however)
Use the two shroomcicles on Luigi. (Talk to the Toadette after the fourth dungeon in the abandoned town, the other is found in a item block in the winding trail) Equip luigi with the Speedy Star Badge. (Found in a secret passage in the Winding Trail) Luigis agility should be 17) The Koopaeleon has an agility of 15. Then go find a Golden Koopeleon and hopefully kill it. (pow block!)
Actually, one thing I just noticed. De-equip the Stone Plated Shirt if you have it on. It lowers agility by one.