halo 3 two questions?

[Kyle D]

OK the first one is when it says get three beat downs one a mythic map what is a mythic map?

and the second one where do you get the new skulls and how?

 

[Maple City Slugger #24]

i only know the first one...
a mythic map would be a map from the mythic map pack...

 

[Gallagator]

the new skulls are on the mythic maps, the download hasn't been announced yet