If the croton plant you are refering to is a codiaeum species, it is moderately toxic. It can cause eye irritation, dermatitis and eczema with contact alone. If consumed, it can cause a burning sensation to the mouth, stomach pain, nausea, vomiting and diarrhoea. In can also cause more severe symptoms such as haemorrhages of the heart, and degradation of the kidneys and liver. I am a horticulturist who writes on plants which are toxic to dogs and cats and all my information has been verified by a veterinarian so the information is correct. Just be careful about this plant around your pets.