Obsessions are "poisonous", one could say, because they tend to lack reality. People who are obsessed with something or someone tend to overly focused on it and often lose sight of the "big picture." Other aspects of their lives tend to fall into the background, if they even continue to exist. Obsessions tend to kill off all other parts of life until nothing exists to that person but their obsession.
it kills you
Obsession at MIS
because they eat milk weed a poisonous plant which makes them poisonous
it is the spikes on it that make it poisonous
God
The ion cyan, CN-.
bibliomania is an obsession of books
Oxalic Acid
Alas, no. It only makes you wish you were dead.
The poisonous toxins injected by its stinger on its tail.
Monarch Butterflies, that's what makes them poisonous.
Some types of mushrooms are poisonous due to naturally occurring toxins that are created within the mushroom. The toxins fall into the following groupings: protoplasmic, neurotoxins, gastrointestinal irritants, and disulfiram-like.
Obsession is 5' 4".