"you musn't eat bear liver. That's full of a poison that'll kill you in minutes."
Lamb's liver
Creative Commons AttributionLamb's liver - Credit: Beck

Although bear's liver doesn't literally contain poison, it does contain so much vitamin A that it is toxic to humans and can cause Hypervitaminous A, a distressing and potentially fatal condition.

Many animal livers are suitable for human consumption and are widely eaten, including calf, chicken and lamb (pictured).