This is a common thing in Bento lunches that I've seen.... a hard-boiled egg, shaped in a mold. Neat trick, I must say. You have to peel the egg and put it in the mold while the egg is still hot, which is kinda tricky. It's not as painful as one might think, however.
The trick is to crack the egg, then run it under cold water for just a few seconds. This gets cold water between the egg and the shell, making it MUCH easier to peel, and also cools down the egg and the shell just enough to peel it without burning your fingers, but not enough so that it won't mold properly.
All in all, a successful experiment, I think. The bunny one exploded during the boiling process, but I decided to try to use it, anyway.... mangled mutant bunny, we called it. DH said he'd be proud to take a mangled mutant bunny to work in his lunch, since mangled and mutant is definitely not "cute" (or should I say "kawaii"?)