It's not "Pink Vynn"

For the Maple Idol, all you need is the most fame in the server (Fame hackers can do this easy) and request for the special medal instead of the normal one. Note that it disappears every month, but as long as you have max fame, you can keep that medal forever.

For the Legendary Hunter Medal, you just need to have the most amount of kills greater than your level in the server.. Just ask for the special medal instead of the regular one.

Note that both of those medals work the same way as the Donor and Boss medals, there can only be 1 of these medals per server at any given time.

I take it not all medals are like this from what you state and the obvious given (ie, Pink Been Slayer, Horntail Slayer, Level 200).

One question though, does the Mu Lung Gym Conqueror, is that a monthly medal as you state with the bossing and donors.