Seewippie, Across the Sea

Seewippie, Across the Sea enters the
battlefield tapped with five slumber counters
on it.
As long as Seewippie 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 Seewippie.
Tap: Add {g}{u}.