Rugged Lake enters the battlefield tapped.
: Add or to your mana pool.
Put Rugged Lake on top of your library: Add to your mana pool.
: Rugged Lake becomes a 1/1 blue and red Dwarf creature with first strike until end of turn. It's still a land.
: Add 
or 
to your mana pool.
to your mana pool. : Rugged Lake becomes a 1/1 blue and red Dwarf creature with first strike until end of turn. It's still a land.
