What kind of caterpillar is this???

Question

Found this on the tree in my yard. The spikes are like needles. They are not soft, they are hard. No I didn't touch it with my finger, I used a stick. It's like an evil caterpillar. Just curious as to what it is. And for all you bug lovers, don't freak out, I'm not gonna kill it. I love nature too.http://bugguide.net/node/view/196036/bgimage

http://bugguide.net/node/view/196037/bgimage

http://bugguide.net/node/view/196034/bgimage

Answer 1

http://en.wikipedia.org/wiki/Giant_Leopa...

Hypercompe scribonia - giant leopard moth.

Answer 2

It looks like a giant leopard moth caterpillar (Ecpantheria scribonia). The pack saddle has a distinct saddle pattern across its back.