Threats against the monster's life, in Mary Shelley's Frankenstein, are numerous.
During the monster's story, chapters eleven through sixteen, the monster reveals that his "life" has not been an easy one. Early in his existence, the monster comes upon a village.
The whole village was roused; some fled, some attacked me, until, grievously bruised by stones and many other kinds of missile weapons, I escaped to the open country, and fearfully took refuge in a low hovel, quite bare, and making a wretched appearance after the palaces I had beheld in the village.
It is here where the monster first comes across those who would wish to end his life.
Later, toward the end of his tale, the monster reveals what happens when he shows himself to the De Lacey family. While the old man is not frightened by the monster, given his blindness, Felix, driven by fear, begins to beat the monster--forcing him to flee from the cottage.
Felix darted forward, and with supernatural force tore me from his father, to whose knees I clung: in a transport of fury, he dashed me to the ground and struck me violently with a stick.
Another person who would have taken the life of the monster if allowed, or if he were a better shot, was a man who thought that the monster had harmed a little girl (in reality, he had saved her from drowning).
On seeing me, he darted towards me, and tearing the girl from my arms, hastened towards the deeper parts of the wood. I followed speedily, I hardly knew why; but when the man saw me draw near, he aimed a gun, which he carried, at my body, and fired.
One last person who wished to take the monster's life was Victor. Multiple times throughout the novel, Victor declares his intent to end the life of the monster.