From ScienceDaily:
Heads of Brazilian frogs are venomous weapons
It’s no surprise that some frogs secrete poison from glands in their skin. But researchers have discovered the first two species of frog, both living in Brazil, that are actually venomous. Not only do the frogs produce potent toxins, but they also have a mechanism to deliver those harmful secretions into another animal using bony spines on their heads.
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The researchers’ calculations suggest that a single gram of the toxic secretion from the other frog species, A. brunoi, would be enough to kill more than 300,000 mice or about 80 humans.
“It is unlikely that a frog of this species produces this much toxin, and only very small amounts would be transferred by the spines into a wound,” Brodie says. “Regardless, we have been unwilling to test this by allowing a frog to jab us with its spines.” More.
You people were better off with the unarmed Canadian snakes, but there is no pleasing you, is there?