Metalhead

Flying When this creature enters, each opponent loses 1 life and you gain 1 life. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

When this creature leaves the battlefield, create a Mutagen token. (It's an artifact with "1, T, Sacrifice this token: Put a +1/+1 counter on target creature. Activate only as a sorcery.")

Sneak R (You may cast this spell for R if you also return an unblocked attacker you control to hand during the declare blockers step.) Jennika's Technique deals 2 damage to each creature.

Flash Turtles you control get +2/+2.

(T: Add G.)

Menace Whenever another permanent leaves the battlefield, put a +1/+1 counter on Super Shredder.

Equipped creature gets +1/+0 for each artifact you control. 4R: Create a token that's a copy of this Equipment. Equip R

Flash When this artifact enters, target creature gets +2/+2 until end of turn. Untap it. 2, T, Sacrifice this artifact: You gain 3 life.