Trapania euryeia is a species of sea slug, a dorid nudibranch, a marine gastropod mollusc in the family Goniodorididae.
The original description included specimens from Réunion, Indonesia (Sulawesi and Bali), Okinawa, the Marshall Islands, Midway Atoll and Hawaii.
It has subsequently been reported from places all across the Indian and Pacific Oceans, including Luzon, Philippines and South Africa.
[3] This goniodorid nudibranch is white, cream or pale yellow in colour, with a pattern of brown patches with fractal-like edges on the body.
Trapania euryeia probably feeds on Entoprocta which often grow on sponges and other living substrata.