The Bolkrog is a large aquatic lizard, closely related to the Lesser Bolkrug. In the past it was believed that the two were members of the same species, however through years of observation, it was discovered that they are merely related species instead.

Bolkrugs stalk through the murky waters of rivers and swamps, feeding on fish and terrestrial creatures that are unlucky enough to have a drink at the wrong place, at the wrong time. Their main M.O. is to use their elongated body to strike like a snake and drag their prey into the water in order to drown it (so a hunting style resembling both a snake and a crocodile). Fish, especially the smaller ones, are simply swallowed whole.

Bolkrugs slither onto land only when they are ready to lay eggs (on land they are very cumbersome). Much like alligators, they make nests from rotting vegetation in order to incubate their eggs. Typically, they choose spots that are hidden from prying eyes, typically in thick bushes and grasses that grow close to the water.