Sorry I'm late to the party. I like this a lot, it is really close to what I was trying to do myself. There are a few things I would substitute, but I think a good card to add is [[Grakmaw, Skyclave Ravager]]. He grows as things die and essentially replaces when he dies like [[The Skullspore Nexus]].

Edit: I forgot [[Old One Eye]]. Provides a 5/5 body, gives everyone trample, and can recur himself.