Cavernous Maw
Land — Cave
Oracle Text
{T}: Add {C}.
{2}: This land 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.
Watch Out
This card involves continuous effects applied in layer order. Type changes (layer 4) are applied before ability changes (layer 6) and P/T changes (layer 7). The order matters — a creature that loses abilities in layer 6 can still get new abilities from effects applied later in the same layer.
If this card's activated ability produces mana and doesn't target, it's a mana ability. Mana abilities resolve immediately without using the stack — opponents can't respond to them. However, abilities that target (even if they produce mana) aren't mana abilities.