Infested Tech Tree   Tier Unit Built at Requires Unit Description (* = costs Terrazine)
                  0 Feederling Brood Hive   Resource Collector
    Egg Cluster   Brood Hive   Extractor     1-3 Brood Mother (L 1-3) Brood Hive   Building creator, mobile production unit
      i         1 Changeling Brood Mother Lvl 1   *Scout, assassin
    Guardian Worm   Brood Mother Lvl 1         1 Roach Brood Mother Lvl 1 Roach den Core anti-ground unit
    h l i         1 Infested Commander Brood Mother Lvl 2 Infested Laboratory *Passive support; builds Infested Colonies
    Evo Chamber   Roach Warren g Arachnid Lair     1.5 Arachnid from Roach Arachnid Lair Core ranged unit
    i   i         2 Scrutinizer Brood Mother Lvl 2   Detector
    Nydus Network   Brood Mother Lvl 2 g Maggot Nest     2.5 Maggot Brood Mother Lvl 2 Maggot Nest Long range splash damage
      l i m       2.5 Infestor Brood Mother Lvl 2 Infestation Versatile caster
    Soaring Roost   Infestation   Laboratory     2.5 Gnat Brood Mother Lvl 2 Soaring Roost Air-to-air fighter
        i   i     2.5 Corruptor Brood Mother Lvl 2 Soaring Roost Core air unit
        Brood Mother Lvl 3   Infested Colony     2.5 Infested Terran Infested Colony   Mass unit with timed life
        i         2.5 Infested Marine Infested Colony   Mass unit with timed life
    Creep Tumor   Plague Boil         3 Plague Host Brood Mother Lvl 3 Soaring Roost Arial Spellcaster
                  3 Aberration Brood Mother Lvl 3 Infested Laboratory Melee tank
            defensive structure   3.5 Brood Host Brood Mother Lvl 3 Plague Boil *Huge anti-ground carrier unit
            production building   4 Brood Lord from Corruptor Soaring Roost, Plague Boil Arial siege unit