Well, my sis had a friend named Issac . . . and everyone called him Icky. So that might work with Ichabod, too, since it's something that's not Icka. XD You could even have a random nickname. For instance, my old college roommate thought my last name sounded like ramen noodle, which she then shortened to Noodle.

But don't worry too much about it. At least he won't be Tentacruel, right? Tee hee . . . pokemon . . . . ^^