Toxic 1 (Players dealt combat damage by this creature also get a poison counter.) Other Rats you control have toxic 1. When Karumonix enters, look at the top five cards of your library. You may reveal any number of Rat cards from among them and put the revealed cards into your hand. Put the rest on the bottom of your library in a random order.

Put target creature card from a graveyard onto the battlefield under your control. You lose life equal to its mana value.

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

Spells you cast have ripple 4. (Whenever you cast a spell, you may reveal the top four cards of your library. You may cast spells with the same name as that spell from among the revealed cards without paying their mana costs. Put the rest on the bottom of your library.)

Each land is a Swamp in addition to its other land types.

Sacrifice a creature: Add one mana of any color.