Complex sentence: If the predator does not take the hint, or have an excellent system against poisons, one of these newts may be its last meal since newts of the genus Taricha have enough toxins in their skin to kill an adult human.
Split into simpler sentences: If the predator does not take the hint, one of these newts may be its last meal. This is because newts of the genus Taricha have enough toxins in their skin to kill an adult human.