StarCraft 2 Spine Crawler tactics allow for interesting maneuvers by Zerg players. The defensive structure allows for uprooting and relocation of itself. Indeed, this structure can be relocated on terrain strategically to serve as the basis for an offensive. The structure can only root itself on Creep.
The Spine Crawler can attack ground targets only however it is very useful for defending choke points and your bases. Spine Crawlers combined with Spore Crawlers can form a nice defensive line that can at least delay your opponent's advance, providing you with additional time to reinforce your lines.
The Spine Crawler can uproot and move around on and off of the Creep, although it moves rather slowly off of the Creep. The Spine Crawler can then be rooted into the Creep. Once rooted it is able to attack. The Spine Crawler will be able to take down a few units before suc[censored] bing to damage. Keep in mind that if this structure rooted and is not on the Creep it will slowly lose health and die.
The Spine Crawler gains a slight damage bonus against armored targets such as Marauders. The bonus is slight however it makes a major difference when you have multiple Spine Crawlers around a defensive line.
The Spine Crawler cannot detect cloaked units unlike the Spore Crawler. As a result it's sometimes a good idea to leave at least one or two Spore Crawlers near Spine Crawlers to stop enemy cloaked ground units from sneaking past them.
Unlike other defensive structures Spine Crawlers and Spore Crawlers need to be perfectly lined up in order to prevent passage of units. Spine Crawlers are sometimes used offensively against an opponent.
Offensive use of Spine Crawlers is a possible strategy provided that you have Creep near the enemy's position. It's especially useful to sometimes use Spine Crawlers against a Zerg opponent as they will always have Creep around their bases. This strategy is most useful before the Zerg opponent creates a Lair as the Hatchery cannot see the edges of the Creep that it spreads.
Against Protoss and Terran opponents you could use an Overlord to spew Creep near an enemy base once you have created a Lair. You could then root the Crawlers in the newly created Creep. Another trick to using Spine Crawlers offensively before Lair tech is to first move a Queen and a Drone to the offensive position.
Once in the correct position you should start morphing the Drone into a Hatchery. Soon after you should cancel the construction of the Hatchery and then get the Queen to place a Creep Tumor on the Creep that has been created. After the Creep Tumor has dug in you now have a forward position to place your Spine Crawlers.