First, I would like to say: I'm sorry if this has already been suggested; I looked through the first page and saw nothing, so figured it would be alright to make this suggestion.
I've always collected animals on sites similar to this - tried to get one of each color or type, etc. So that was my plan when I registered here: Collect each color variant possible for each type of creatu. As my collection grows, I see I'm taking more time to check my collection to see if I already have the creatu/color that had just hatched out of an egg.
I've thought about using the "Pet Log" as a way to track which colors I already have, and sometimes think that was its actual purpose, but I just didn't want to leave the freshly hatched creatu's page. To make collecting easier, I thought adding a chart like the "Pet Log" or something similar as something that will pop up when you hatch a creatu (and maybe when you visit the "Hatch Slots" as well). It doesn't have to be a complete chart; just something to tell you whether or not you already have, say, a natural Zenirix or an albino Zenirix.
And, again, I'm sorry if this has already been suggested and has made you waste your time reading it.
Pet log does this. If you want to see it open a new tab. No reason to clutter up the hatch page with something that already exists. The entire purpose of the pet log is to tell you what you currently have, lol.