Self-mill is key here, so some Dredge.
Pharika’s Two-Colored Cards
I like the flavor of black-green, so there’s plenty of cards I’d like to use here.
Catacomb Sifter is a very efficient creature. The scrying ability is very strong, especially with what I want to do with this deck.
Deadbridge Chant gives continuous card advantage in a fun way. Also, if you get one of the delve cards I put into the cube (with Phenax), this can be very strong.
Drown in Filth is both self-mill and fair removal. It can miss badly, but at least it mills.
Gift of the Deity has an interesting effect in this deck, since its going to have plenty of deathtouch.
Grave-Shell Scarab provides Dredge.
Lotleth Troll is an interesting card that’s very hard to evaluate. Its pretty bad card disadvantage, but at the same time, getting those creatures into your graveyard can be good as well.
Necrogenesis is an alternative payoff for self-mill if you can’t find Pharika.
Nyx Weaver is good self-mill, but also can get you something from the graveyard.
Pharika’s Mender is flavorful.
Rot Farm Skeleton is continuous self-mill.
Spiderspawning is very strong. Maybe too strong.
Varolz, the Scar-Striped could be another payoff card.
This is kind of hard, actually, but I guess this:
First, Deathtouch enables easy trading with quite a few creatures. You get benefit from those creatures anyhow.
Typhoid Rats and Pharika’s Chosen are easy choices. So is Graveblade Marauder, although it can be quite oppressive at times. Ukud Cobra is somewhat unassuming, but very powerful. Lastly, one of the best creatures around: Vampire Nighthawk.
Harvester of Souls is in the Deathtouch camp, but also gives you other benefits, so its in.
Also, a couple of Dredge cards: Necroplasm can be very poor in this deck at times, but its an interesting card. Stinkweed Imp doesn’t quite have Deathtouch, but almost, so its actually in two camps here.
Green does have something more though. It can force confrontations through Fights. The best way to do this Setessan Tactics.
I also want Nemesis of Mortals in the cube, because of how nicely it works with self-mill.
This leaves room for one Dredge-card: Golgari Grave-Troll (assuming I can find one cheap enough).