Whats the spine crawler?

These kind of units are perfect for the Zerg because of how quickly and how necessary it is for them to expand it cuts down on their expenses a lot to not have to keep producing new defensive structures, although this can also be a downfall if the player is sloppy or lazy it would be a weak wall that once broken would crumble their entire base.
By the way you can now create more then one queen at a time. Only unit that is restricted in that way is the mothership last time I checked. Kudos for making the queen more bad ass though, the old queen didn't hold the title well.

 

What made the queen Un-unique?
You would also easily be able to move creep crawlers to close bases.
Also you could also attack zerg with them if they were close to you and with good units to protect them.