Would using The Golgari Champion to scavenge Consuming Aberration produce any counters?
Yes.
Consuming Aberration’s first ability is what’s called a characteristic-defining ability (CDA), which among other things means it functions in all zones, not just the battlefield. Consuming Aberration’s CDA still defines its power and toughness even when it’s in the graveyard and exile.
Therefore, when you scavenge Consuming Aberration and the scavenge ability resolves, the effect will check Consuming Aberration’s power and see that it’s equal to the number of cards in your opponents’ graveyards. Then the effect will put that many +1/+1 counters on whatever creature you targeted.





