Surma is a character in the Finnish mythology of Kalevala. Surma is a terrible beast, embodies sudden, violent death and guards the gates of the Tuonela to prevent escape. It is often described as being a large dog with a snake-tail and can turn you into stone (with a stare). An often-used Finnish metaphor is surman suuhun "into Surma's mouth", as if the victim was mauled to death by Surma.
Surma also means kill, or specifically a kill and the verb surmata, to kill or to slay, is derived from it.