Peanuts are not toxic to cats, but they are not recommended as a regular part of a cat's diet. Cats are obligate carnivores and require animal protein to thrive, which peanuts do not provide. Peanuts can pose some risks such as choking hazards due to their hard texture, potential allergic reactions, and digestive issues. Additionally, peanuts are high in fat and calories, which could contribute to obesity and related health problems if fed frequently. Salted, spiced, or coated peanuts should always be avoided as they contain toxic or unhealthy ingredients for cats. Overall, peanuts are not harmful in small, plain, unsalted amounts, but they are nutritionally redundant and riskier snacks compared to appropriate cat treats and foods.