Even though the new Golgari mechanic was revealed this week, I've been working on my own alternate since I saw HavelockV's challenge on Goblin Artisans, a fellow designer blog.
Last week's Sunday card was the first example of Harvest. Here's another:
Golgari traditionally use the graveyard as a resource, as evidenced by their last guild mechanic, Dredge. I wanted to keep the same flavor while expanding on the idea. I chose Harvest because of the tension it brings. I like how you can give up casting the actual spell for the surprise factor of the Harvest ability or you can wait until the creature's dead and use it whenever.
Harvest isn't limited to creatures, though. Here's an example of a card that might not have a useful target while it's sitting in your hand.
Have a good week, and don't be afraid to Harvest!