3 drop that you are missing: Lifebane Zombie

I just realized having Underworld Cerberus and Scavenging Ooze in the same deck is kind of counter productive...

You use Scavenging Ooze to get rid of their graveyard so they have no creatures when Underworld Cerberus dies. I was thinking Lifebane Zombie but the double black seems difficult to cast early. I'm also not too sure about Ghor-Clan Rampager being in the deck.

You can't use Scavenging Ooze if you currently have Underworld Cerberus in play. You'd have to make Ooze big and then play the Cerberus.

Im making a similar deck, Underworld Cerberus is such a sweet card specially against control. Ever think about throwing in Lotleth Troll its discard ability is nice with the cerberus also Tymaret, the Murder King is a good sac for cerberus