David Shale / Fang Tooth {Anoplogaster cornuta} close-up of head showing teeth, from the Mid-Atlantic Ridge, 2600m

Solvin Zankl / Common fangtooth (Anoplogaster cornuta) deep sea species from Atlantic Ocean close to Cape Verde. Captive.

Solvin Zankl / Common fangtooth (Anoplogaster cornuta) portrait, deep sea species from Atlantic Ocean off Cape Verde. Captive.

Thomas Marent / Mandrill (Mandrillus sphinx) male in defensive posture, Lekedi Natural Preserve, Gabon

Cyril Ruoso / Drill (Mandrillus leucophaeus) alpha male calling, Pandrillus Drill Sanctuary, Cross River State, Nigeria

David Shale / Fangtooth (Anoplogaster cornuta) portrait, Mid-Atlantic Ridge, North Atlantic Ocean

Mark Bowler,Mark Bowler / Siberian musk deer (Moschus moschiferus) male with tusks grooming, captive, Midlothian deer enclosure, UK, vulnerable species

David Shale / Fang Tooth {Anoplogaster cornuta} close-up of head showing teeth, from the Mid-Atlantic Ridge, 2600m

Michael & Patricia Fogden / Vampire Bat (Desmodus rotundus) portrait, Costa Rica

Norbert Wu / Fangtooth (Anoplogaster cornuta) has bony, hard body, unlike most deep sea fish, San Diego, California

Norbert Wu / Fangtooth (Anoplogaster cornuta) has bony, hard body, unlike most deep sea fish, Eastern Pacific

LYNN M. STONE / Fangs of Eastern diamondback rattlesnake. Florida, USA {Crotalus adamanteus}

Bence Mate / Silhouette of an African leopard (Panthera pardus pardus) snarling, Mkuze, South Africa. September. 'White Fang' - this leopard bared its fangs to the hyenas threatening his prey. Eventually the leopa...

Tony Wu / Striped poison-fang blenny mimic (Petroscirtes breviceps) male inside bivalve shell, guarding eggs laid by different females adhered to inside of shell. Shizuoka Prefecture, Honshu, Japan. June.

Chris Mattison / Cyprus tarantula (Chaetopelma karlamani), fangs on underside, close up. Cyprus. March.

Magnus Lundgren / Wild Wonders of China / Striped poison-fang blenny (Meiacanthus grammistes) Xiaoliuqiu Island, Taiwan. Venomous species.

Magnus Lundgren / Wild Wonders of China / Striped poison-fang blend (Meiacanthus grammistes) Xiaoliuqiu Island, Taiwan

Georgette Douwma / Striped poison fang blenny (Meiacanthus grammistes) in a bottle. Lembeh Strait, North Sulawesi, Indonesia.

Daniel Heuclin / Horned viper (Vipera ammodytes) held in human hand, showing fangs, Turkey.

Juergen Freund / Striped poison-fang blenny (Meiacanthus grammistes) swimming out of discarded bottle home, surrounded by rubbish, Sulawesi, Indonesia. November.

Juergen Freund / Striped poison-fang blenny (Meiacanthus grammistes) using a discarded oil container as its home, Sulawesi, Indonesia. November.

Juergen Freund / Striped poison-fang blenny (Meiacanthus grammistes) in its discarded bottle home, surrounded by rubbish, Sulawesi, Indonesia. November.

Juergen Freund / Striped poison-fang blenny (Meiacanthus grammistes) swimming above its discarded bottle home, surrounded by rubbish, Sulawesi, Indonesia. November.

Ashley Cooper / Alpenglow at sunrise on Annapurna South and Annapurna Fang, Nepal. December 2012.

Ashley Cooper / Night sky over Annapurna South and Annapurna Fang, with a glow from the moon setting behind the peak. Annapurna Sanctuary, Himalayas, Nepal, December 2012.

Emanuele Biggi / Regal jumping spider (Phidippus regius) captive male with iridescent fangs. Italy.

Emanuele Biggi / Regal jumping spider (Phidippus regius) captive male with iridescent fangs. Italy.

Emanuele Biggi / Regal jumping spider (Phidippus regius) captive male with iridescent fangs. Italy.

Emanuele Biggi / Regal jumping spider (Phidippus regius) captive male with iridescent fangs. Italy.

Paul Bertner / Huntsman Spider (Megaloremmius leo), Andasibe-Mantadia National Park, Antananarivo, Madagascar

Thomas Marent / Aruba Rattlesnake (Crotalus durissus) fangs, native to South America

Solvin Zankl / Common fangtooth (Anoplogaster cornuta) deep sea species from Atlantic Ocean close to Cape Verde. Captive.

Thomas Marent / Gelada Baboon (Theropithecus gelada) male in defensive display, Simien Mountains National Park, Ethiopia

Thomas Marent / Mandrill (Mandrillus sphinx) male in defensive posture, Lekedi Natural Preserve, Gabon

Thomas Marent / Drill (Mandrillus leucophaeus) male in defensive posture, Afi Mountain Wildlife Sanctuary, Nigeria

Thomas Marent / Drill (Mandrillus leucophaeus) male yawning, Afi Mountain Wildlife Sanctuary, Nigeria

Thomas Marent / Buff-cheeked Gibbon (Nomascus gabriellae) female in defensive posture, Phnom Tamao Wildlife Rescue Center, Cambodia

Anup Shah / Eastern Chimpanzee (Pan troglodytes schweinfurthii) male, twenty-two years old, in aggressive display, Gombe National Park, Tanzania

Solvin Zankl / Viperfish (Chauliodus sloani) specimen from the North Atlantic deep sea.

Suzi Eszterhas / Proboscis Monkey (Nasalis larvatus) dominant male yawning, Sabah, Borneo, Malaysia

Sergey Gorshkov / Leopard (Panthera pardus) yawning, Sabi-sands Game Reserve, South Africa

Nick Garbutt / Colombian Pink-toed Tarantula (Avicularia metallica) in defensive posture, Paujil Nature Reserve, Magdalena Valley, Colombia, South America.

Pete Oxford / Eastern Diamondback Rattlesnake (Crotalus adamanteus) in defensive posture, Little Saint Simon's Island, Georgia

Daniel Heuclin / Egyptian cobra (Naja haje) with head raised, hood expanded and fangs on display, on near Taroudant, Morocco.

Piotr Naskrecki / Tarantula (Theraphosidae) in defensive posture, Gorongosa National Park, Mozambique

Daniel Heuclin / Amazon tree boa (Corallus hortulanus) close up of face, baring fangs, French Guiana

Anup Shah / Japanese Macaque (Macaca fuscata) male yawning while resting at edge of geothermal spring, Jigokudani Monkey Park, Japan

MYN / Andrew Snyder / Common lancehead (Bothrops atrox) with person holding jaw open to show fangs, Kanuku Mountains, Guyana. Meetyourneighbours.net project

Thomas Marent / Golden Snub-nosed Monkey (Rhinopithecus roxellana) male in threat display, Qinling Mountains, Shaanxi, China

Thomas Marent / Golden Snub-nosed Monkey (Rhinopithecus roxellana) male in threat display, Qinling Mountains, Shaanxi, China

Thomas Marent / Golden Snub-nosed Monkey (Rhinopithecus roxellana) male in threat display, Qinling Mountains, Shaanxi, China

Cyril Ruoso / Drill (Mandrillus leucophaeus) adult male calling, Pandrillus Drill Sanctuary, Cross River State, Nigeria

Cyril Ruoso / Drill (Mandrillus leucophaeus) adult male yawning, Pandrillus Drill Sanctuary, Nigeria

Cyril Ruoso / Drill (Mandrillus leucophaeus) adult male yawning, Pandrillus Drill Sanctuary, Nigeria. Sequence 3/3

Cyril Ruoso / Drill (Mandrillus leucophaeus) adult male yawning, Pandrillus Drill Sanctuary, Nigeria. Sequence 2/3

Piotr Naskrecki / Lesser Spear-nosed Bat (Phyllostomus elongatus) mouth, Suriname

Michael D. Kern / Blue Fang Tarantula, (Ephebopus cyanognathus) captive from South America

Michael D. Kern / Blue Fang Tarantula, (Ephebopus cyanognathus) captive from South America

Michael D. Kern / Blue Fang Tarantula, (Ephebopus cyanognathus) ventral view, captive from South America

Piotr Naskrecki / Jumping Spider (Bathippus sp) with enlarged chelicerae which are used to catch prey, Papua New Guinea

Juergen Freund / Fang blenny (Plagiotremus sp.) emerging from its hole. Lembeh Strait, North Sulawesi, Indonesia

Juergen Freund / Shorthead fang blenny / Striped poisoned-fang blenny (Petroscirtes breviceps). Lembeh Strait, North Sulawesi, Indonesia.

Georgette Douwma / Striped poison-fang blenny mimic (Petroscirtes breviceps) mimic of Striped blennie (Meiacanthus grammistes), which possesses a pair of large grooved fangs in the lower jaw with associated venom glands...

Georgette Douwma / Striped poison-fang blenny mimic (Petroscirtes breviceps) mimic of Striped blennie (Meiacanthus grammistes) which possesses a pair of large grooved fangs in the lower jaw with associated venom glands....

Michael D. Kern / Black mamba (Dendroaspis polylepis) with mouth open and fangs exposed, captive, from Africa

Albert Lleal / Western Diamondback Rattlesnake (Crotalus atrox) retracting and repositioning fangs, native to North America

Thomas Marent / Blue Fang Skeleton Tarantula (Ephebopus cyanognathus) in defensive posture, French Guiana

David Shale / Fang Tooth {Anoplogaster cornuta} close-up of head showing teeth, from the Mid-Atlantic Ridge, 2600m

David Shale / Fang Tooth {Anoplogaster cornuta} close-up of head showing teeth, deepsea, from the Mid-Atlantic Ridge, depth 2600m

Robert Valentic / King brown snake {Pseudechis australis} held in hand to expose fang sheath, Sturt NP, New South Wales, Australia

Albert Lleal / Sun Spider (Solifugae) SEM close-up view of spider attacking a crustacean

Albert Lleal / Wolf Spider (Lycosa tarantula) SEM close-up view of face at 14x magnification

Christian Ziegler / Army Ant (Eciton hamatum) portrait of a soldier with large mandibles, Barro Colorado Island, Panama

Pete Oxford / Eyelash Viper (Bothriechis schlegelii) eating a mouse, venomous, arboreal, Esmeraldas, Ecuador

Pete Oxford / Eyelash Viper (Bothriechis schlegelii) eating a mouse, venomous, arboreal, Esmeraldas, Ecuador

Pete Oxford / Emerald Tree Boa (Corallus caninus) showing independent mobility of four jaws, Amazon, Ecuador

Heidi & Hans-Juergen Koch / Hunting Spider (Cupiennius salei) close-up detail of the chelicerae which contain poison, like other tropical spiders introduced to Europe in fruit boxes, native to Central America

Michael & Patricia Fogden / Hog-nosed Pit Viper (Porthidium nasutus) swallowing a Rain Frog (Eleutherodactylus sp) note use of fangs to manipulate frog into mouth, rainforest, Costa Rica

Michael & Patricia Fogden / Hog-nosed Pit Viper (Bothrops nasutus) predating Middleamerican Ameiva (Ameiva festiva) lizard note the use of fangs to manipulate prey into snake's mouth, rainforest, Costa Rica

Michael & Patricia Fogden / Hog-nosed Pit Viper (Bothrops nasutus) defensive throat display, rainforest, Costa Rica

Claus Meyer / Venom dripping from snake tooth, Brazil

Birgitte Wilms / Striped Blenny (Meiacanthus grammistes) in its burrow surrounded by Christmas Tree Worms (Spirobranchus giganteus) 40 feet deep, Galapagos Islands, Ecuador

Norbert Wu / Fangtooth (Anoplogaster cornuta) has bony, hard body, unlike most deep sea fish, Eastern Pacific

Norbert Wu / Fangtooth (Anoplogaster cornuta) cleared and stained to show bones (Red) and cartilage (Blue) deep sea

Norbert Wu / Fangtooth (Anoplogaster cornuta) adult portrait underwater showing open mouth and sharp teeth, Eastern Pacific

Mark Moffett / Chinese Habu (Trimeresurus mucrosquamatus) being milked for venom, Tam Dao National Park, Vietnam

Mark Moffett / Tarantula (Theraphosidae) underside with retracted fangs can be seen at top of frame, Chile

Mark Moffett / Kerengga Ant-like Jumper (Myrmarachne plataleoides) males fight showing elongated jaws ending in fangs which are usually sheathed, Sri Lanka

Mark Moffett / Kerengga Ant-like Jumper (Myrmarachne plataleoides) male in fighting posture showing elongated jaws ending in fangs which are usually sheathed, Sri Lanka

Mark Moffett / Northern Green Jumping Spider (Mopsus mormon) two males fighting, male on top has fatally stabbed the other with his fang, Singapore

Robert Valentic / New Guinea death adder {Acanthophis laevis} female showing fang, Indonesia, captive

Robert Valentic / Death adder, male showing fang sheath {Acanthophis antarcticus} South Australia

Sean Crane / Stump-tailed Macaque (Macaca arctoides) male in defensive posture, Kaeng Krachan National Park, Thailand

Heidi & Hans-Juergen Koch / Western Diamondback Rattlesnake (Crotalus atrox) being milked for anti-venom, Germany

Thomas Marent / Gelada Baboon (Theropithecus gelada) males fighting, Simien Mountains National Park, Ethiopia

Thomas Marent / Yunnan Snub-nosed Monkey (Rhinopithecus bieti) in threat display, Yunnan Province, China