The Arctic alligatorfish[2] (Aspidophoroides olrikii) is a fish in the family Agonidae.

[4] It is a marine and brackish-water dwelling fish which is known from the Arctic, the northwestern Atlantic and northwestern and northeastern Pacific Ocean, including Canada, Greenland, Siberia, the Barents Sea, the White Sea, the Kara Sea, the Chukchi Sea, the Bering Sea, the Bering Strait, and the Anadyr Gulf.

It dwells at a depth range of 7–520 metres, in salinities of 30–35 ppt, and leads a benthic lifestyle, inhabiting sand and mud bottoms.

Males can reach a maximum total length of 8.6 centimetres.

[3] The diet of the Arctic alligatorfish consists of amphipods such as Dyopedos porrectus and Paradulichia typica, bivalves such as Macoma calcarea, ostracods, isopods, and nemertine worms.