When Bat Colony enters the battlefield, create a 1/1 black Bat creature token with flying for each mana from a Cave spent to cast it. Whenever a Cave enters the battlefield under your control, put a +1/+1 counter on target creature you control.

{T}: Add {C}. {2}: Cavernous Maw becomes a 3/3 Elemental creature until end of turn. It's still a Cave land. Activate only if the number of other Caves you control plus the number of Cave cards in your graveyard is three or greater.

({T}: Add {G}.)

{T}: Add {C}. Other Caves you control have "{T}, Pay 1 life: Add one mana of any color."

Hidden Cataract enters the battlefield tapped. {T}: Add {U}. {4}{U}, {T}, Sacrifice Hidden Cataract: Discover 4. Activate only as a sorcery. (Exile cards from the top of your library until you exile a nonland card with mana value 4 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Hidden Courtyard enters the battlefield tapped. {T}: Add {W}. {4}{W}, {T}, Sacrifice Hidden Courtyard: Discover 4. Activate only as a sorcery. (Exile cards from the top of your library until you exile a nonland card with mana value 4 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Hidden Necropolis enters the battlefield tapped. {T}: Add {B}. {4}{B}, {T}, Sacrifice Hidden Necropolis: Discover 4. Activate only as a sorcery. (Exile cards from the top of your library until you exile a nonland card with mana value 4 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Hidden Nursery enters the battlefield tapped. {T}: Add {G}. {4}{G}, {T}, Sacrifice Hidden Nursery: Discover 4. Activate only as a sorcery. (Exile cards from the top of your library until you exile a nonland card with mana value 4 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Hidden Volcano enters the battlefield tapped. {T}: Add {R}. {4}{R}, {T}, Sacrifice Hidden Volcano: Discover 4. Activate only as a sorcery. (Exile cards from the top of your library until you exile a nonland card with mana value 4 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Calamitous Cave-In deals X damage to each creature and each planeswalker, where X is the number of Caves you control plus the number of Cave cards in your graveyard.

Choose three. You may choose the same mode more than once. • Search your library for a Cave card, put it onto the battlefield tapped, then shuffle. • Put three +1/+1 counters on a Cave you control. It becomes a 0/0 Elemental creature with haste. It's still a land. • Destroy target enchantment.