* Lilies: All parts of lilies (including the pollen) are highly toxic to cats, even in small amounts. Ingestion can cause acute kidney failure leading to death.
* Chocolate: Theobromine, a stimulant found in chocolate, is toxic to cats. The darker the chocolate, the more toxic it is. Chocolate can cause vomiting, diarrhea, hyperactivity, tremors, seizures, and heart problems, ultimately leading to death if left untreated.
It's important to keep these substances away from cats and to seek immediate veterinary attention if you suspect your cat has ingested either.