Sometimes I knit something just to say I’ve done it.  I once knit a Frilled-Neck Dragon for that reason.  I mean, how many people can say they’ve knitted that?  I’ve knit hippos in tutus and entire herds of ponies.  Anyway, this hat sort of captivated me.  It was designed by  Hannah Ingalls.  It is a free pattern available at the on line magazine Knitty. There is an entire Ravelry group devoted to sharing the experience of knitting trilobites.  So long as you know how to read charts, it is an easy and satisfying knit.  Now I can say I’ve knitted Trilobites.