You're thinking the snake species Chuckus norrisi, Samuel L Jackson would describe it as a m
Actually, I was quoting a line from the "Commodore's steps" play by Venedikt Erofeev. One of the characters there - a capo of a mental hospital room - compares another character to a snake - a mamba - which, according to him, is so poisonous that from its bite a man dies thirty seconds before he's bitten. Attribution must be given, and better late than never.