The Northern Constrictor (Th."Srebsteg") was a snake of the Boa-family, native to the pinewoods of the Northern Peninsula and most closely related to the sand-boa. It was grey in colour, 5-8 feet in length and non poisonous, for it killed its prey by constriction.
Notes
In the "Shade of the sinking plain"-sourcebook, the snake called merely a "Boa constrictor", a name usually only applied to the type of Boa native to the Americas or Caribbean. The Northern Constrictor however is loosely based on the extinct Siberian Boa.