The holotype of Oohkotokia, MOR 433 consists of a crushed but rather well preserved skull that measured 375 mm, axial material, a partial scapula, several thin-walled osteoderms, cervical armour, a very large humerus, and other fragments.

Its tail club was made of several plates of bone, permeated by soft tissue, which allowed the absorption of thousands of pounds of force.

There was sufficient morphological detail to conclude that Oohkotokia is a different animal than its relatives, Euoplocephalus tutus, Dyoplosaurus acutosquameus, and Scolosaurus cutleri.

[1] Arbour and Currie (2013)[4] found that Oohkotokia shares diagnostic features with Scolosaurus, including cervical half ring morphology and squamosal horn shape.

Lithologies, invertebrate faunas, and plant and pollen data suggest that during the Campanian, this region experienced a long dry season and warm temperatures.

The Two Medicine Formation has produced the remains of oviraptorosaurs, ornithopods, the nodosaur Edmontonia, the ceratopsians Achelousaurus, Brachyceratops, Cerasinops, and Einiosaurus among others, Troodon, the dromaeosaurids Bambiraptor, Dromaeosaurus and Saurornitholestes, and the tyrannosauroids Albertosaurus, Daspletosaurus and Gorgosaurus.

[6][7][8][9] The skull of Oohkotokia, specimen MOR 433 is crushed but is overall reasonably well preserved on its dorsal and lateral surfaces, but its midline is offset to the animal's left side.

The recovered fossil material ranges from red to grey, but the coloration is not thought to bear any taphonomic significance, and the variation most likely arose from differential weathering.