My wife always brings eggs to work, and they tend to be crushed in the backpack. I designed and printed this egg container. Also uploaded files for 2 color printing.
I recommend using PETG, since its food safe, but I assume that PLA would be ok as well. If you print the botton+top part in PLA you could print the clamp in PETG for example, to get at more flexible part. Prints without supports, and with the two connecting faces onto the bed, this might result in some stringing/bad bridging at the top on the inside, but nothing that really matters. Could also be printed with supports if you want, but it will add extra time and filament cost. I've measured the largest egg I could find in our package, inside is 54x45