Cast Seance. Bring back a Thragtusk. Populate. Bask in the fear in your enemy's eyes.
Dawntreader elks to gum up the ground early, then mana fix, then seance back for more mana.
Dreg manglers for their haste and possible scavenging.
Pack Rats and Vitu-Ghazi guildmages so you can bring them back with seance and immediately populate itself. Seems pretty cool to me.
Thragtusks because Thragtusks, and slimes to kill their lands/whatever.