The Infested Spine Crawler is a grotesque, organic siege unit with a segmented, spine-like body that tapers to a sharp point. Its surface is covered in pulsating, veined flesh with patches of hardened chitin plating, giving it a rough, uneven texture. The creature's coloration is a sickly blend of purples and greens, with glowing yellow pustules that emit a faint bioluminescent light, hinting at its Zerg origins. Distinctive design elements include its ability to burrow into the ground, leaving only its spiked spine visible, and its maw-like appendage that can extend to attack enemies with surprising reach.