Wall Creeper

The Wall Creeper is a spider-like enemy that can be found in caverns, spawning in and around Spider Nests, only in pre-Hardmode worlds. Wall Creepers are capable of climbing background walls (as seen in their dens) as well as through platforms, but revert to acting like a fighter enemy when there is no background wall.

Trivia

 * The quote of the Skeleton Merchant suggests that he may have become skeletal due to this spider.
 * The Wall Creeper cannot crawl through Platforms.

History
Grimpeur de murs 월 크리퍼