Stompers -
Passive (unless attacked / approached)
often in groups of 3+
Very common
Easy to avoid attacks (keep moving around)
Drops 300 essence
Deals low physical damage
Low health
Best hero to kill - Summer (when stompers in large group)

Spitters -
Aggressive (hides under ground when not approached)
Often on it's own but can spawn in groups of 3+
Un-Common
Easy to avoid attacks (move left and right)
Drops 400 essence
Deals DoT (damage over time)
Low health
Best hero to kill - Any

Lurkers -
Passive (unless they have spawned on a harvester and will attack on sight) will turn aggressive when shot at) *note can fly
Spawns on it's own but can be clusterd around 5+ (wont attack player unless shot at / will all wake up if one is shot at)
Common
Drops 250 essence
Deals Physical damage
Very low health
Best hero to kill - Any

Hives -
Passive (unless shot at)
Spawns on it's own in set locations
Projectiles shot at player can be easy / hard to avoid depending on hero (use cover to bait)
Drops 5000 essence
Deals high DoT (damage over time)
Very high health
Best hero to kill - (don't attack solo best with 4 players / depends on the game mode) Bugg / Summer / Earl / Mendoza (any high DPS hero)
*note there is a weak point - shoot the blue roots*