Blood Crawler

Blood crawler is a tick found in Crimson. It can crawl on the background walls freely in any direction, but will traverse the terrain like the player if there is none. It's a deadly enemy for beginners. They are immune to the Poisoned and Venom debuffs. It follows the Spider AI.

It seems to have knockback resistance when climbing walls. It is also able to move underwater while climbing on walls.

Bugs
Occasionally, It crawls on the sky.