Skullspider by Brent P. Newhall; CC-BY-3.0
Spawned in abandoned graveyards and poorly maintained battlefields, skullspiders are large, venomous predators about the size of a cat. Unlike the single web of a typical spider, each skullspider will spread several thick webs over graves, crypts, bushes, and trees and feed indiscriminately on anything that gets caught there. They are also viciously territorial and will attack any creature that breaks any of their webs.
When attacking, a skullspider emits a high-pitched shriek and rattles its skull-shaped head. Any creatures seeing and hearing this must make an appropriate Fright check or become stunned for one round after the attack. If successfully bitten, the skullspider’s poison slows the target, then immobilizes it.