Trample, haste Crew 2 (Tap any number of creatures you control with total power 2 or more: This Vehicle becomes an artifact creature until end of turn.)

This creature can't block. When this creature dies, create X 1/1 black Rat creature tokens with "This token can't block," where X is the amount of damage dealt to it this turn.

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 {B}.)

Menace Whenever this creature enters or attacks, create two 1/1 black Rat creature tokens with "This token can't block." Then if you control five or more Rats, each Rat you control gets +2/+0 until end of turn.

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.)

At the beginning of combat on your turn, return target Vehicle card from your graveyard to the battlefield. It gains haste. Return it to its owner's hand at the beginning of your next end step.

Menace When this Vehicle enters, it deals damage equal to twice the number of Vehicles you control to target creature or planeswalker an opponent controls. Crew 4

Whenever this Vehicle attacks, you may sacrifice another artifact or creature. If you do, put a +1/+1 counter on this Vehicle and it gains menace until end of turn. Crew 2 (Tap any number of creatures you control with total power 2 or more: This Vehicle becomes an artifact creature until end of turn.)

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.