Malevolent Reptiles and Amphibians/Examples

Mythology

 * Egyptian mythology:
 * Apep
 * Sobek
 * Greek mythology:
 * Gorgons:
 * Medusa
 * Lamias
 * Jormungandr (Norse mythology).

Literature

 * Tick-Tock the Crocodile (Peter Pan).
 * Kaa (The Jungle Book).
 * Basilisk, Nagini (Harry Potter).

Comics

 * DC:
 * Killer Croc
 * Copperhead
 * Turtle
 * Marvel:
 * Lizard
 * Abomination
 * Serpent Society
 * Jormungand
 * Toad

Animation

 * The Mighty Ducks:
 * Saurians
 * Lord Dragaunus
 * Siege
 * Chameleon
 * Wraith
 * Hista (The Legend of Tarzan).
 * Disney's The Lion Guard:
 * Makuu
 * Ushari
 * Kiburi
 * Kenge
 * Ora
 * Strange Cobra
 * Ben 10 franchise:
 * Ssserpent, King Koil
 * Albedo, Ultimate Albedo, Dark Matter
 * Subdora, Prisoner 775, Negative Chamalien
 * Negative Arctiguana, Negative Ultimate Arctiguana
 * Attea, Emperor Milleous
 * Mutant Frog
 * Gaterboy
 * Mutant Reptile Leader
 * Scooby-Doo:
 * Creeping Creatures
 * Gator Ghoul
 * Snake Demon
 * Motoshondu
 * Lake Monster
 * Evil Turtle (The Amazing World of Gumball).
 * TMNT:
 * Leatherhead
 * Slash
 * Lord Hebi
 * The Penguins of Madagascar:
 * Savio
 * Barry
 * Kung Fu Panda: Legends of Awesomeness:
 * Fung
 * Lidong
 * Fu-Xi
 * Demon Frog (Kirby: Right Back at Ya!).
 * Snake Man (Mega Man).
 * LEGO Ninjago:
 * Great Devourer
 * Pythor P. Chumsworth
 * Skales
 * Fangtom
 * Acidicus
 * Disney's Robin Hood:
 * Sir Hiss
 * Captain Crocodile
 * Brutus and Nero (Disney's The Rescuers).
 * Joanna the Goanna (Disney's The Rescuers Down Under).
 * Snake Jafar (Disney's Aladdin).
 * Disney's The Princess and the Frog:
 * Ian the Gator
 * Marlon the Gator
 * Rango:
 * Rattlesnake Jake
 * Tortoise John
 * Bad Bill
 * Viper (The Secret Life of Pets).
 * Randall Boggs (Disney/Pixar's Monsters, Inc).
 * Lou the Goanna (FernGully: The Last Rainforest).
 * Don Bluth's Thumbelina:
 * Grundel Toad
 * Mrs. Toad
 * Flushed Away:
 * The Toad
 * Le Frog

Television

 * Doctor Who:
 * Silurians
 * Slitheen
 * Ice Warriors
 * Krafayis

Films

 * Heston (Ella Enchanted).
 * Budzo (Zambezia).
 * Lizzie (Rampage).
 * Tao Tei (The Great Wall).
 * Constantine (Muppets Most Wanted).
 * Skullcrawlers (Kong: Skull Island).
 * Zilla (Godzilla (1998)).
 * Giant Boa (King Kong (1976)).
 * Lizard (The Amazing Spider-Man).
 * Sandworms (Beetlejuice).
 * Buraki (Dragon Wars).
 * Mr. Jones (Toy Story of Terror!).
 * Rodrigue (April and the Extraordinary World).
 * Crocosaurus (Mega Shark vs Crocosaurus).
 * Dinocroc:
 * Dinocroc
 * Supergator

Videogames

 * Super Mario Bros.:
 * King Bowser
 * Prince Bowser Jr.
 * Koopalings
 * Koopas
 * Koopa Troopas
 * "King" Wart
 * Mortal Kombat:
 * Reptile
 * Donkey Kong:
 * Kremlings
 * Bazuka
 * Big Klaptrap
 * Green Kroc
 * Junior the Giant Klaptrap
 * Kaboing
 * Kaboom
 * Kackle
 * Kalypso
 * Kaptain Skurvy
 * Kasplat
 * Kass
 * Kerozene
 * King K. Rool
 * Kip
 * Klank
 * Klasp
 * Klinger
 * Kloak
 * Klobber
 * Klubba
 * Kludge
 * Klump
 * Knocka
 * Koin
 * Kopter
 * Kosha
 * Krash
 * Krimp
 * Krook
 * Krumple
 * Krunch
 * Krusha
 * Kudgel
 * Kuff 'n' Klout
 * Kutlass
 * Re-Koil
 * Resident Demon
 * Skidda
 * TNT Knocka
 * Coily (Q*bert series).
 * Kraid (Metroid series).
 * Yawn (Resident Evil).
 * Killer Croc (Batman: Arkham series).