Venomous animals

Numerous animal species naturally produce chemical toxins which are used to kill or incapacitate prey or as a defense against predators. Venomous animals deliver these toxins as through a, , or other specially evolved mechanism.

Venoms have evolved to serve a wide variety of purposes. Their intended effects can range from mild fleeting discomfort to paralysis and death, and they may be highly selective in which species they target, often making them harmless to all but a few specific organisms. Because the definition of "venomous" can be extremely broad, this list includes only those animals with venom that is known or suspected to be medically significant for humans or domestic animals.

s
Strictly speaking, all spiders and scorpions possess venom, though only a handful are dangerous to humans. Spiders typically deliver their venom with a bite from piercing, fang-like ; scorpions sting their victims with a long, curved mounted on the.

Spiders

 * s (Atrax and Hadronyche spp.)
 * s (Phoneutria fera and Phoneutria nigriventer)
 * All (Latrodectus spp.), including the black widows, button spiders, Australian  (L. hasseltii), and the endangered  of New Zealand (L. katipo)
 * (Steatoda spp.)
 * All (Loxosceles spp.), including the  (L. reclusa) and  (L. laeta)
 *  spp.
 * s (Missulena spp.)
 *  spp.
 *  spp.
 * A few species of (in addition to chelicerae, some also have s)

Scorpions
Of more than a thousand known species of, only a few dozen have venom that is dangerous to humans, most notably the , including:
 *  spp.
 * (Leiurus quinquestriatus)

Insects

 * s
 * s
 * Some s
 * Certain lepidopteran s are covered in urticating hairs for defense

Other arthropods

 * Many species of
 * The  is a centipede-like  with a long segmented body and scores of legs which display a swimming motion. They live in underground  caves of Mexico and Central America. Although blind, they are formidable predators, and feed on the shrimp that share their underground pools.


 * sting using microscopic cells called s, which are capsules full of venom expelled through a microscopic lance. Contact with a jellyfish tentacle can trigger millions of nematocysts to pierce the skin and inject venom.
 * Some s, including the (Physalia physalis)
 * s
 * Some s

Many species of octopus, squid, and cuttlefish make use of venom when hunting their prey.
 * The (Hapalochlaena spp.) produce, which is extremely toxic to even the healthiest adult humans, though the number of actual fatalities they have caused is far lower than the number caused by spiders and snakes, with which human contact is more common.

Fish
There are at least 1,200 species of venomous fish, including:
 * es (Synanceia spp.)
 * es (Pterois spp.)
 * es
 * es (' and ' spp.)
 * es (Siganus spp.)
 * Goblinfishes (' and ' spp.)
 * (Ablabys taenianotus)
 * Striped blenny ()
 * s
 * s
 * s (Echiichthys vipera and Trachinus spp.)
 * Most s
 * A few species have venomous "stings" behind their fins, including:
 * The (Cnidoglanis macrocephalus)
 * The (Plotosus lineatus) and other es (Neosilurus spp.)
 * The (Plotosus lineatus) and other es (Neosilurus spp.)

Snakes

 * s (Dendroaspis spp.), including the (D. polylepis)
 * (Dispholidus typus)
 * All true s (Naja spp.), including the (Naja naja)
 * (Ophiophagus hannah)
 * s (Bungarus spp.), including the (Bungarus caeruleus)
 * s (Bothrops spp.), including the (B. lanceolatus) and the  (B. asper)
 * s (Lachesis spp.)
 * (Agkistrodon contortrix) and (Agkistrodon piscivorus)
 * s (Micrurus, Leptomicrurus, and Micruroides spp.)
 * (Acanthophis spp.)
 * (Hydrophis belcheri)
 * (Aipysurus duboisii)
 * (Pseudonaja textilis)
 * (Oxyuranus microlepidotus)
 * (Oxyuranus scutellatus)
 * (Daboia russelii)
 * Most s (Crotalus and Sistrurus spp.)
 * (Echis carinatus)
 * s (Notechis spp.)

Lizards

 * (Heloderma suspectum)
 * (Heloderma horridum)
 * Some members of the genus , such as the (V. komodoensis),  (V. giganteus) and  (V. varius).

Mammals
Only a few modern mammal species are capable of producing venom; they are likely the last living examples of what was once a more common trait among the mammals. The definition of "venomous" becomes less distinct here, however, and whether some species are truly venomous is still disputed.
 * (Talpa europaea)
 * (Ornithorhynchus anatinus)
 * (Neomys fodiens)
 * (Neomys anomalus)
 * (Blarina brevicauda)
 * (Blarina carolinensis)[disputed]
 * (Blarina hylophaga)[disputed]
 * Both species of, the (Solenodon cubanus) and the  (S. paradoxus)
 * (Nycticebus spp.)[disputed]

Dinosaurs
Some scientists have proposed that  had a venomous bite, but recent evidence suggests otherwise.