Dream about killing a large snake is unfortunately a warning alert for self-doubt and fears of not achieving your goals. You are lacking some sort of social life. You may be feeling emotionally dirty or guilty and are trying to wash away the shame. The dream points at your nurturing side and maternal feelings. You need to break out of your shell and let others know your true self.
Killing a large snake is unfortunately destruction, hostility and the frustrations that you are experiencing
An issue or a task at hand may be trickier than you had anticipated. There is a significant change that is quickly approaching. The dream hints foiling or thwarting someone's plans. You feel that you are not measuring up.