The green casual Eldrazi Drones in Rise of the Eldrazi are the better of the bunch. Nest Invader is a low drop bear that yields one token.
Kozilek's Predator is a little heavier, and can net you two Spawns.
Broodwarden is a bit of a late drop for Modern, but in casual all is well with casting it since you get to buff all of your Spawn tokens. It does not buff Scion tokens, though.
In with the new.
Blisterpod: your sacrificial lamb for Black/Green sac strategies.
Brood Monitor: Nice ETB for the AVR cube, and is fair given that you use 6 mana to get a total of 6 for attacks. Still... there are vanilla creatures that are better for this casting cost, the point here is to use those three tokens to generate mana for an Eldrazi.
Call of the Scions: good Limited card. It can even help in Constructed.
Unnatural Aggression: good pit fighting at Instant speed is good. A great battle trick with Deathtouch on your side.
Eyeless Watcher: Great name, by the way. ETB effect for the AVR cube.
Last, but not least, From Beyond: The Awakening Zone of this set (At the beginning of your upkeep, you may put a 0/1 colorless Eldrazi Spawn creature token onto the battlefield. It has "Sacrifice this creature: Add
Link to Part 9