To clairfy the above writeups:

The name "creme" for the filling is a bit misleading. While it is "creamy" in the sense of being fluid, it is much thicker and more viscous than cream (going so far as to become solid if chilled sufficiently). It is also slightly grainy and hair-curlingly sugary.
In keeping with the egg metaphor, the creme layer of the egg is white on the outside and yellow in the centre.

Here's a map:
  / __ \
 / /  \ \
 | |yy| |
 | |yy| |
 \ \w_/ /
c = chocolate
w = white sugary goo
y = yellow sugary goo

As for the mascot, I think they're just merging two popular Easter symbols: the Easter Bunny and the easter egg, which presumably comes from a chicken. Ironically, they are including elements from an even older tradition, in which Easter was a fertility festival (one instantiation is the old Celtic festival of Beltaine, now appropriated by the neopagans). The bunny was originally chosen as a symbol because of its famed fecundity, so having it lay the egg (also a fertility symbol) brings the celebration full circle, as it were.