The Bunny Egg is an Easter item. It appears only during the ARK: Eggcellent Adventure and ARK: Eggcellent Adventure 2 event.
Bunny Eggs are laid by the special BunnyDodos and BunnyOviraptors. These creatures only appear during the Eggcellent Adventure event. They wear Bunny Ears, which makes them easily distinguishable from normal Dodos and Oviraptors.
In Eggcellent Adventure 2 they are laid by mate boosted wild Dodos.
They were also used to summon the DodoRex.
The eggs had a light grayish color. They could be placed somewhere and painted with Dye.
In addition to its preset paint regions, you can doodle on the Bunny Egg by "attacking" it with a Paintbrush, which will open the "Apply Paint" Menu. Then, click and drag your cursor over the 3D model (like a paintbrush) to draw anything you want. See Painting for more information on doodling.
A promotional image from the Eggcellent Adventure with examples of dyed Bunny Eggs.