Aiteng ater is a species of sea slug, a marine gastropod mollusc in the family Aitengidae.

[2] The specific name ater is from the Latin language and means black, in reference to the appearance of the slug on the mud.

[2] However, in the absence of a separated visceral hump, Aiteng ater is able to retract its head under the frontal part of the notum.

[4] Aiteng ater is an amphibious species which lives in mangrove forests in the intertidal zone, on the mud.

[2] Inside the bodies of individuals of Aiteng ater, there were found to be white elongated endoparasites; these are as yet unstudied.