Rhabdophis tigrinus, the Tiger Keelback, is native to East and Southeast Asia. It preys on amphibians, including the Japanese toad, Bufo japonicus. It secretes cardiotonic steroids known as bufadienolides (BDs) from its skin. Consumption of BDs is typically fatal in other snake species, but, R. tigrinus displays resistance to these toxins. After consuming toads, R. tigrinus sequesters BDs into glands on its neck. The adrenal glands of R. tigrinus are enlarged in comparison to similar species.
Grover, Clayton; McCleary, Ryan; Kojima, Yosuke; Foster, Alex; and Savitzky, Alan, "Testicular Microanatomy of Rhabdophis tigrinus During theBreeding and Nonbreeding Seasons" (2017). Biology Posters. Paper 143.