te·tro·do·tox·in 
(tĕ-trō′də-tŏksĭn)
(tĕ-trō′də-tŏksĭn)n.
A potent neurotoxin, C11H17N3O8, found in many pufferfishes and certain other animals, including some salamanders and crabs.
[Shortening and alteration of New Latin Tetraodōn, pufferfish genus (Greek tetra-, tetra- + New Latin -odōn, -odon (so called because members of the genus have two upper and two lower teeth)) + TOXIN.]