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.

{T}: Add {C}{C}.

Flying Whenever another nontoken creature you control dies, you may pay 2 life and exile it. If you do, create a token that's a copy of that creature, except it's 1/1 and has toxic 1. (Players dealt combat damage by it also get a poison counter.)

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.) Whenever a creature you control becomes the target of a spell, target opponent gets a poison counter.

When this creature enters, create a 1/1 black Rat creature token with "This token can't block." Whenever another creature you control dies, put a +1/+1 counter on this creature.

({T}: Add {B}.)

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.) When this creature dies, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)