The Dull Green Bird Egg is one of the many bird eggs that can be collected on the island of Matumada. It can be found in the Featherpedia, despite not being a feather. It is only obtained from the Bird Nest as a possible egg out of the many that be revealed from the Bird Nest.
In appearance, the Dull Green Bird Egg is a small, green egg with light green spots on its shell. Besides that, it appears to be shiny as evident from the light's reflection in the center of the egg.
The Dull Green Bird Egg does not have any relevant purposes in-game and as such, it can be sold to a selling vendor at a selling price of 5,500 gold.