Atarka's command is literally the only way i could see Undergrowth scavenger being decent, Drop him, next turn swing, drop land (or fetchland) and +1/+1, so he's a 4/4, or a 5/5 if you have a fetch. Who know's maybe there's a naya deck somewhere with exquisite firecraft, atarka's command, dromoka's command, and all the guys that get bigger in green (mana gorger hydra, den protector, deathmist raptor, Undergrowth Champion).
These are the type of idea's i get then go build a deck in cockatrice, give up on after a few hours, then 3 months later all of the sudden its in a top 8 at scg and im like, but you just get destroyed by control!