Flounders Egg

I was farming in the Tombs for a while and then suddenly after killing last boss i came across a Flounders Egg.
I have no idea what it looks like or how rare it is or how much i sells for. Mind answering that please? tyvm :)

kk dw i now know its a dodo, still how rare is it and how much does it sell for?

look in cs?

Havent looked yet, also cs mostly rips people off. General deals done in towns will be better

flounders cost 50 plat. if im right.