The Great Juggernaut

Trample

When this creature enters, you take the initiative.

Whenever this creature attacks, exile the top card of your library. If you've completed a dungeon, you may play that card this turn without paying its mana cost. Otherwise, you may play that card this turn.

Menace

When this creature enters, create two 1/1 black Rat creature tokens with "This token can't block."

At the beginning of your upkeep, you may sacrifice another creature. If you do, put a +1/+1 counter on this creature and exile the top card of your library. You may play that card this turn.

At the beginning of your upkeep, exile the top card of your library. You may play that card this turn.

Lucky Slots — At the beginning of combat on your turn, scry 1, then exile the top card of your library. You may play that card this turn. When you exile a card this way, target creature you control gets +X/+0 until end of turn, where X is that card's mana value.

Reach

Start your engines! (If you have no speed, it starts at 1. It increases once on each of your turns when an opponent loses life. Max speed is 4.)

Max speed — At the beginning of your upkeep, exile the top card of your library. You may play that card this turn.

At the beginning of your upkeep, exile the top card of your library. If it's a nonland card, you may cast that card this turn.

Whenever you cast your third spell in a turn, you may transform Vance's Blasting Cannons.