Lv50 creature in lower level area?

[Alukah]

http://ffxiv.gamerescape.com/wiki/The_Hunt

Don't try to solo A ranks or S ranks, B ranks are worthless unless you get the weekly bill from your GC (once you hit 50), when A or S rank spawns you will most likely see a flood of shouts of people asking for invite, the best way to get full rewards from those monsters is by partying up with other people.

[Enkidoh]

http://ffxiv.gamerescape.com/wiki/The_Hunt

Don't try to solo A ranks or S ranks, B ranks are worthless unless you get the weekly bill from your GC (once you hit 50), when A or S rank spawns you will most likely see a flood of shouts of people asking for invite, the best way to get full rewards from those monsters is by partying up with other people.

They're not entirely worthless, as they still count towards the Hunt achievements regardless if you have the Hunt Bill or not, so if you're after the quest titles from them it's still worth doing. Or if you're bored and are feeling particularly bloodthirsty (I like to hunt B rank NMs for sport myself even if I don't have the Hunt Bill for them).