content: The platypus is one of the few living mammals to produce venom. Males have a pair of spurs on their hind limbs which secrete venom that is only seasonally active to breeding season, supporting the theory that the use of venom is for competition of mates only, not protection. While the spur remains available for defense outside of breeding season, the platypus's venom gland lacks secretion. While the after effects are described as excruciatingly painful, this venom is not lethal to humans. -From Wiki