This deck died down over time, especially when Mox Opal was originally banned (Mox Opal is back, but there are plenty of stronger combo options in Modern than Cheerios)
I think the best fodder are ones that replace themselves or have some sort of effect when they enter the battlefield since theyve already provided value coming in, so the body is fine to use going out
Legendary Creature - Elemental Phyrexian Sea-Dasher Octopus Mutate (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own
Pauper Its without a doubt the most budget friendly format which contains only common types, from prices ranging 15 to 80
The payoff you get just from this card alone is enough to make me think that youd strongly consider expanding into Grixis colors if you already have a demon tribal deck
It's generating resources, in this case a creature