Certain eggplant varieties do have sharp spines on them but that being said is definitely atypical. What you are seeing there is probably a throwback or reversion in genetic terms. I have seen throwbacks with tomato seeds quite often where a few seeds will produce a "wild form" of tomato where the fruits were no larger than a pea.
I found that this was a more prevelant problem with seeds from a cheaper producer.
That is a cool lookin' plant none the less.
I just hope you don't walk in one day and hear "Feed me Seymore!"