Plot Summary: Name that Spider

Griddle readers. I need your help. Please help me identify my new pet. He lives in my community garden plot, and his name is WTF?-Why-Am-I-So-Big-And-Scary.

Hopefully we have some arachnid experts in our midst. Is this guy dangerous or just intimidating?

Picture, after the jump. (Sorry the angle isn't better; I was scared.)