Good question.
Numbers 3, 4 and 5 must belong to any ot the few oviparous habitat animals we have, other than ostrich and cassowary. Number 3 is more symmetrical and less "egg-shaped" so it could be from any crocodile. Tortoise eggs are much more spherical than any of those 5.
Numbers 4 and 5 are probably from the other birds... Maybe 4 is from peafowl and 5 from penguin? Just a guess after a quick Google images search.
I think number 6 doesn't belong to any specific animal, it says "painted egg" because it's flexicolor, and that's all... If it were bigger you could say it's a hint for emu
