1. Lily flowers: These are highly toxic to cats, and can even be fatal. Even ingesting a small portion of the flower or licking the pollen can cause serious damage to a cat's kidneys.
2. Common houseplants containing toxins: such as pothos, ivy, spider plant, etc. The toxins in these plants may cause gastrointestinal upset and other adverse reactions in cats.
3. Crassulaceae plants: Some Crassulaceae plants contain toxic components, such as cactus. If a cat accidentally ingests them, it may cause digestive problems and discomfort.

4. Onions and garlic: Onions and garlic are common seasonings, but they are toxic to cats. They can cause red blood cells to rupture, leading to health problems such as anemia.
5. Sago Palm: The sago palm is a common indoor and outdoor plant. All parts of it (including leaves and fruit) are poisonous to cats and can cause serious poisoning.