Foods in the Solanaceae family (for example, Deadly Nightshade) contain the toxic Glycoalkaloid Solanine, but pre-made pet foods containing ripe tomatoes are safe in small amounts.
Chocolate is toxic to cats as well: theobromine, which can be found in dark and unsweetened chocolate, is responsible for chocolate toxicity.
Grapes and raisins can be toxic to dogs, so the ASPCA advises against feeding them to cats. Keep them at bay to avoid any potential dangers.
Avocados contain Persin, which can make cats sick. Fat causes gastroenteritis and pancreatitis. Avoid serving cats guacamole or its spoons/forks.
Alcohol is poisonous to cats. Clean up after yourself and avoid leaving open containers. Hand sanitizer, mouthwash, fermenting fruits, and bread dough can all expose cats to alcohol.
Onions & garlic can cause anemia in cats due to their N-propyl disulfide. Cats shouldn't eat full cloves of garlic or raw onion pieces & can also be exposed thru powder found in chips, soups, & seasonings.