Species Gasteracantha cancriformis - Spinybacked Orbweaver
I had never seen a spider like this before, eep!! It is harmless. Doesn't it look like it has a little face and it is wearing a funny hat with it's arms & legs sticking out?
This species can be easily distinguished from all other spiders. Females may be 5 to nearly 9 mm in length, but 10 to 13 mm wide. They have six pointed abdominal projections frequently referred to as "spines." The carapace, legs, and venter are black, with some white spots on the underside of the abdomen. The dorsum of the abdomen is, typically for Florida specimens, white with black spots and red spines. Specimens from other areas may have the abdominal dorsum yellow instead of white, may have black spines instead of red, or may be almost entirely black dorsally and ventrally.