Nidorino

Zoologically, these creatures really don't seem to be based on anything in particular, unless you want to consider them a fictional branch of Synapsid, the extinct animals combining both "mammalian" and "reptilian" anatomical features, though there isn't any mammal or reptile in our world with a coating of venom-filled skin barbs. This was back when a lot more pokemon are taxonomically ambiguous "monsters," and not always drawn so specifically from mythology or science.