From Liquipedia Starcraft 2 Wiki
The Spine Crawler is a Zerg static defense structure that deals 25 damage to ground units with a 5 point damage bonus to armored units. Although similar to the Sunken Colony, the Spine Crawler has the distinct ability to Uproot itself and Root in a new location, making it somewhat mobile and more flexible in use. The Spine Crawler can only attack with its Impaler Tentacle while rooted and is thus left defenseless while uprooted. If the Creep around the Spine Crawler is gone, the Spine Crawler will slowly lose hitpoints until Creep has been restored around it. Note that a Spine Crawler does not lose the hitpoints if it uproots, even when off Creep.
Against a Protoss Zealot rush you can expect it to succumb to 2 Zealots per Spine Crawler. So one Spine Crawler can hold off two Zealots and kill one of them before dying, and two Spine Crawlers can hold off 3 Zealots and dies if attacked by four of them [killing 3 Zealots before dying]. Things improve if you can use them in natural Choke Points. Spine Crawlers have 1 more range than Stalkers' 6 range and do heavy damage to Stalkers. The only advantage a Stalker has over a Zealot is range, and thus it can engage and do damage to the Spine Crawlers before a Zealot can, possibly negating some of the choke point advantage.
(to insert defensive capabilities against Terran / Marines)
 Offensive Uses
Although it can only be burrowed on creep, there have been a few instances of offensive use, similar to a Protoss cannon rush. This is enabled by an Overlord generating creep near an opponents location or an expansion that is about to be taken by an opponent.
A Spine Crawler rush can be performed even earlier in a ZvZ due to the existence of creep in an enemy Zerg's base. Spine Crawler rushes in ZvZ are most effective before the opponent has a Lair. This is due to the sight range of a Hatchery being slightly smaller than the creep range of the Hatchery. This gives a small area on the edge of the creep where a Spine Crawler can be placed outside the vision of the Hatchery. A Lair has greater vision than a Hatchery and does not have this blind spot.
Instead of an Overlord (requires Lair), creep for offensive Spine Crawlers may also be generated via the following procedure:
- Move a Queen and a Drone to the desired creep location.
- Start morphing a Drone into a Hatchery at the desired location.
- Cancel the morphing Hatchery and immediately place a Creep Tumor on the creep left by the cancelled Hatchery.
In ZvP, a common Lategame strategy is to build large numbers of Spine Crawlers to act as support for Brood Lords, the Spine Crawlers being positioned beneath the Brood Lords in order to deter Stalkers from Blinking underneath the Brood Lords and taking them out, since Spine Crawlers deal additional damage to Armored units (such as Stalkers) and are very potent against such units when in large numbers. In addition, Infestors can be used to root Stalkers in place (via the use of Fungal Growth) should they decide to Blink beneath the Brood Lords, preventing them from Blinking back and escaping the Spine Crawlers. Assuming the creep spread is sufficient, the Zerg player can slowly move the Spine Crawlers "wall" (by uprooting and rooting them) towards the opponent's base, along with the Brood Lords and the rest of the army, in a way that is somewhat reminiscent of a Terran player leapfrogging Siege Tanks towards the ennemy's base.
Unlike other buildings, which completely block units if their building patterns meet at all, Spine Crawlers only block unit pathing if they are placed in perfect horizontal or vertical rows to each other. If a Spine Crawler is offset from another even by only one building placement space then most units can pass through including large units like Queens. The only units which cannot pass through this gap are Archons, Siege Tanks, Ultralisks, Thors, Colossi, Spore Crawlers, and other Spine Crawlers.
 Patch Changes
|Patch 7 (version 0.9.0.14621B)|
|Patch 9 (version 0.11.0.15097)|
|Patch 11 (version 0.13.0.15250)|