Jenova, Ancient Calamity

At the beginning of combat on your turn, put a number of +1/+1 counters equal to Jenova's power on up to one other target creature. That creature becomes a Mutant in addition to its other types.
Whenever a Mutant you control dies during your turn, you draw cards equal to its power.

Ace, Fearless Rebel

Nitro-9 — Whenever Ace attacks, you may sacrifice an artifact. When you do, put a +1/+1 counter on Ace, then it fights up to one target creature defending player controls.
Doctor's companion (You can have two commanders if the other is the Doctor.)

Ygra, Eater of All

Ward—Sacrifice a Food.
Other creatures are Food artifacts in addition to their other types and have "{2}, {T}, Sacrifice this permanent: You gain 3 life."
Whenever a Food is put into a graveyard from the battlefield, put two +1/+1 counters on Ygra.