Beyond being horrifying, these would take up a lot of room in your purse. Forget putting them in your pocket.
These limited edition, Japan-exclusive isopod cases are perfect for the marine biologist in your life. Or, possibly, for the person in your life who enjoys scaring others. Now, as these things are Japanese, I can't tell if the inspiration is the attempt to make some kind of iPhone/isopod pun (like my brain's been trying to do ever since I saw these), but that would almost be worse than just wanting to make isopod phones.