Hi, welcome to Pokefarm Wiki! Thanks for your edit to the Eggs page.
I have information about the Landorus egg description:
" A light orange Egg adorned with a red gem-like object. It causes powerful sandstorms nearby."
Terrakion egg description:
" A gray Egg with a fist symbol on the front. It seems more active than other Eggs."
I hope to be able to help out with gathering information as I obtain it.