This is a Fork and Continuation of Spiders 2.0 by TheCyberBrick

Nyf's Spiders 2.0

Vanilla spiders are not yet creepy enough for you? You wish spiders would actually climb properly?!
Spiders 2.0 enables regular spiders and cave spiders to walk along walls and ceilings and it also improves their AI such that they can find their way around almost any obstacle.