as far as I know the toxin in a tomato frog's skin functions like a latex glue and causes the predator's mouth to become clogged as well as causing it to get stuck to leaves and other items on the ground preventing the predator from consuming the frog. Not all anurans secrete what are considered to be typical skin toxins however, a green tree frog is not an acceptable cage mate for a green tree frog due to other issues.
Ed
(Message edited by ed on June 06, 2006)