Prepare to get wrecked by zombies in modern!!! Now backed by Dredge!!
Zombies that recur:
Gravecrawler
Dread Wanderer
Skaab Ruinator
Prized Amalgam
Haunted Dead
18 creatures in total!!
Gravecrawlers and Dread Wanderers are the main force of our zombies. You can stay aggro with Gravecrawler and defensive/aggro with Dread Wanderers as needed. Also, you can cast Gravecrawlers for great synergy with Cryptbreaker, serving as tap fodder to draw cards early and late game!! And to top it off, they each serve as discard fodder for Lotleth Troll, making him so much more valuable as the game goes on.
Skaab Ruinator is a well pay off by having a huge body in the air, with the "drawback" of exiling 3 creatures from the graveyard almost always being achievable. Creatures to consider exiling would be those that don't recur, Cryptbreaker, Lotleth Troll, and Stinkweed Imp. I would also consider exiling Dread Wanderer if need be because he's a worse Gravecrawler. Any other creatures, I would try not to exile or exile as a last resort.
With all of these creatures being brought back from the graveyard, it'd be remiss not to include Prized Amalgam, whom reanimates herself for free whenever we cast or reanimate another zombie from the graveyard. This zombie just wants to swing ALL THE TIME. DO IT. Don't hold back with this zombie and let that sweet body go to waste.
There are a couple reasons to add Haunted Dead to the deck. First, she synergizes with Dredge by being another zombie that doesn't care if we mill it. Second, if our board gets wiped or our zombies otherwise removed, she can be brought back on the cheap, while filling our graveyard, and allow us to recur Gravecrawlers and Prized Amalgams like our board didn't flinch at all!! Third, she provides combat tricks. Wait to recur her until your opponent declares attackers so you can chump with the spirit token she produces. Lastly, recur her before going to an opponents end phase so that the Prized Amalgams trigger at the beginning of their end phase and you can then untap them during your turn, as though coming in tapped meant nothing!!
Non-recurring zombies:
Cryptbreaker
Lotleth Troll
Stinkweed Imp
Only 12 creatures don't come back but serve critical roles!!
Cryptbreaker can help go wide early game and draw cards late game. Discard recurrable zombies or dredge pieces to make 2/2 zombie tokens, or set up your advantage by discarding the heartthrob of the deck, Skaab Ruinator! Late game, tap down as many copies as you have of him out in combination with Dread Wanderer, and especially Gravecrawler since he doesn't come in tapped, to generate massive card advantage at the cost of a bit of life. Are you a swamp-mage? Of course you are since life is a resource!!
Lotleth Troll, sweet Lotleth Troll. You have 22+ creatures to discard to Lotleth Troll, most of which can be brought back cheaply or freely. Apply massive pressure with this tall, stubborn zombie who refuses to die and wants to hit as hard as he can! And if he dies or gets dredged away, he's just more exile fodder for Skaab Ruinator. He's useful in his life AND his death!! Yay, zombies!!!
Finally, enable your zombies with Dredge by filling your graveyard using Stinkweed Imp and Life from the Loam!! This allows you to find critical pieces fast and have them in the graveyard to cast at your convenience while having enough creatures to exile to Skaab Ruinator. Thanks, Dredge!!!
As for the non-creature spells, Life from the Loam basically ramps from all the dredging, Inquisition of Kozilek provides both information on an opponents strategy and a way to disrupt their disruption of your strategy, and Grisly Salvage fills the graveyard while getting you a much needed land or creature.
Note: I have considered replacing this with Traverse the Ulvenwald as we can enable delirium and tutoring for a specific card can sometimes be more advantageous however, I feel that Grisly Salvage does too much for the deck though the replacement is a fun one to consider. But build it how you want! Just make your opponents fear your Undead Horde!!
