Arixmethes, Slumbering Isle

Arixmethes, Slumbering Isle enters
the battlefield tapped with five slumber counters
on it.
As long as Arixmethes has a slumber
counter on it, it's a land. (It's not a creature.)
Whenever you cast a spell, you may remove
a slumber counter from Arixmethes.
{t}Add {u}{g}