Favorinus tsuruganus is a species of aeolid nudibranch, a sea slug.

[3] The back and oral tentacles are opaque white and there is a yellow patch on the front of the head.

The cerata have black tips with the digestive gland duct being orange, a distinguishing feature of this species.

[4] This species occurs in Japan, more rarely in eastern Australia down to around Sydney, and has a wide western Pacific distribution.

[3][5] Favorinus tsuruganus feeds on the eggs of a wide range of other opisthobranchs, in particular, Hexabranchus.