Main characters are always tough to pin down. They need to be the 'straight man' (or woman), but still be distinct and interesting. They also get the most scrutiny, both from a design and technical standpoint. Eggs went through a lot of iterations, with a bunch of designers throwing in their version (many can be seen in the great Art Of Boxtrolls if you haven't already taken a look). Mike Smith, Kent Melton and I helped contribute a lot to the final character you see on screen. I did these sketches while working with Kent on the maquette sculpture. After a certain point in the process though, the sketches only can take the character so far. A stop-motion puppet need to exist in a real space, and Kent is a master at designing characters in 3 dimensional space.
The one question I have is, is his name "Huevos" in the spanish version?