(Isle Catacombs isn't a spell.)
Isle Catacombs enters the battlefield tapped unless you control an enchantment.
Green spells cost more to play.
: Add or to your mana pool.
Put Isle Catacombs on top of your library: Add to your mana pool.
more to play.
: Add 
or 
to your mana pool.
to your mana pool. 
