All Rats have fear. {T}, Sacrifice a Rat: Create X 1/1 black Rat creature tokens, where X is the number of Rats you control.

Black creature spells you cast cost {1} less to cast. Whenever you cast a creature spell, each opponent loses 1 life and you gain 1 life.

As an additional cost to cast this spell, sacrifice a creature. Draw two cards.

Target creature gets -1/-1 until end of turn for each Swamp you control.

Target creature gets -2/-2 until end of turn.

({T}: Add {B}.)

This creature gets +1/+0 for each other Rat you control. A deck can have any number of cards named Rat Colony.