Solenodon

From the introduction:

The Solenodon is a strange mammal related to the hedgehog. At less than 3 lbs and fewer than 2 ft long, one would hardly consider this nocturnal forager a dangerous creature. That is, until one is bitten by the Solenodon. It is one of the few real-world mammal that has a poisonous bite, secreting toxic saliva that can affect the nervous system and cause excruciating pain.