http://en.wikipedia.org/wiki/Tarantula Tarantulas are arthropods. Arthropods have a 3 segmented body, including a head, thorax and abdomen. However some of them have a cephalothorax and an abdomen, only having 2 body regions. (Head and thorax are the same region in these ones)
I chose this one because I've always been interested in tarantulas. Most people are afraid of them, but I think they're very interesting.