Popular beast alternate modes

When arriving on Earth, there are millions of animal species a Cybertronian might scan for an Alternate mode. Some genera, however, are extremely popular with Cybertronians.

(NOTE: For the sake of saving space, characters on this list who share a toy mold are combined into a single line.)

Molluscs

Cephalopods

• Tentakil (G1) / Tentakil (Masterforce) / Tentakil (Energon) / Scylla
• Claw Jaw / Scuba / Ikard
• Tako Tank
• Dead End (BWN)

Arthropods

Insects

Stag Beetles (family Lucanidae)

• Shrapnel / Zaptrap
• Chop Shop
• Insecticon (BW)
• Beetle

Rhinoceros beetles (family Scarabaeidae)

• Bombshell / Salvo
• Barrage
• Ram Horn / Motorarm

Grasshoppers and locusts (order Caelifera)

• Kickback (G1) / Shothole
• Ransack (G1)
• Scourge (BW)

Spiders

Generation 1 / Beast Era

• Arachnid
• Tarantulas

Black Widow Spiders (Latrodectus mactans)

• Blackarachnia (same mold as Tarantulas but supposedly different species)
• Transmetal Blackarachnia
• Transmetal-II Blackarachnia / Arcee (G1)
• BM Blackarachnia / Crystal Widow

Animated

• Blackarachnia (Animated)

Crabs

• Cancix
• Octopunch
• Rampage / Shokaract
• Razorclaw / Rockbuster
• Razor-Sharp

Scorpions

Generation 1/Beast Era

• Double Punch (G1)
• Pincher
• Poison Bite
• Scorpia
• Scorponok (G1) / Black Zarak
• Scorponok (BW) / Sandstorm / Double Punch (BW)
• Quickstrike (BW) (partially)
• Scorpulator

Unicron Trilogy

• Scorponok / Dark Scorponok

Transformers (2007)

• Scorponok

Fish

Manta Rays (Manta birostris)

• Seawing//Kraken/Terrormander/Energon Seawing (unreleased)
• Manta Ray
• Depth Charge

Sharks

Great White Shark (Carcharodon carcharias)

• Overbite/Sea Phantom/Energon Overbite (unreleased)
• Cybershark (Transmetal)/Sky-Byte

Hammerhead Shark (genus Sphyrna)

• Cybershark/Hellscream/Overbite
• Air Hammer (partially)
• Hammerstrike

Sawshark (genus Pliotrema and genus Pristiophorus)

• Sharp Edge

Dinosaurs

Tyrannosaurus

Generation 1/Beast Era

• Grimlock / Overkill
• Megatron / T-Wrecks
• Trypticon / Gigastorm

Unicron Trilogy

• Grimlock
• Megatron
• Predacon

Animated

• Grimlock

Triceratops

Generation 1/Beast Era

• Slag
• Guiledart / Triceradon
• Knockdown / Ironlunge

Unicron Trilogy

• Triceradon

Animated

• Snarl

Stegosaurus

Generation 1/Beast Era

• Snarl
• Slugfest
• Saberback / Striker

Unicron Trilogy

• Snarl

Velociraptor

Generation 1/Beast Era

• Dinobot / Grimlock / Thrustor
• Dinobot II / Rapticon
• Razor Claw

Unicron Trilogy

• Grimlock

Pterosaurs

Pteranodon

Generation 1/Beast Era

• Swoop
• Terrorsaur / Fractyl / Terranotron (A.K.A. Swoop)
• Terranotron (BM)

Unicron Trilogy

• Terrorsaur / Ravenus
• Swoop

Animated

• Swoop

Dragons

Generation 1/Beast Era

• Megatron / Cryotek
• Deathsaurus (partially)
• Galvatron / Unicron
• Nightscream / Dragoyell
• Savage
• Snapdragon

Robots in Disguise

• Megatron/Galvatron (partially)

Unicron Trilogy

• Scourge

Reptiles

Crocodylians

American alligator (Alligator mississippiensis)

• Skullcruncher / Skull
• Megatron (BW)
• Terragator (partially)
• Soundwave (BW)

Turtles

Snapping turtles (genus Chelydra and Macroclemmys)

• Snaptrap / Turtlar / Halfshell
• Snapper
• Terragator (partially)

Snakes

Cobras (genus Naja and others)

• Cohrada
• Nightviper (even though vipers aren't cobras)
• Cobrabreast

Birds

Eagles (order Accipitriformes)

• Squawktalk
• Eaglebreast
• Silverbolt (Magnaboss) / Skywarp (BW)
• Silverbolt (Fuzor) (partially)
• Dreadwing (Classics) / Wedge Shape

Condors (genus Vultur and Gymnogyps)

• Laserbeak / Buzzsaw / Garboil / Sundor
• BM Silverbolt

Hawks and falcons (order Falconiformes)
Generation 1 / Beast Era

• Hawkbreast
• Wingspan
• Doubledealer
• Airazor

Unicron Trilogy

• Airazor (Armada)

Mammals

Bats

• Mindwipe
• Nightscream
• Optimus Primal / Onyx Primal
• Ratbat
• Skar / Clouder
• Sonar
• Soundwave
• Batbreast

Carnivores

Bears (genus Ursus)

• Chainclaw
• Grizzly-1 / Polar Claw / Survive
• Icebird
• Kuma Kinkin

Canines

Wolves / Dogs (Canis lupus)

Generation 1/Beast Era

• Carnivac
• Wolfang (Maximal) / Wolfang (Predacon) / K-9 / Max-B
• Weirdwolf
• Sixshot (partially)

Unicron Trilogy

• Snarl

Felines

Jaguars (Panthera onca)

• Ravage/ Glit / Howlback
• Panther
• Battle Ravage
• Jaguarbreast

Tigers (Panthera tigris)

• Rampage
• Snarl
• Tigerbreast
• Toraizer
• Tigatron
• Tigerhawk (winged) / Razorclaw

Lions (Panthera leo)

• Angela / Dark Eggleo / Eggleo
• Lio Convoy
• Leobreaker / Nemesis Breaker
• Lionbreast
• Leonicus
• Prowl / Lio Junior
• Razorclaw
• Snarl / Alpha Trion
• Steeljaw
• Under-3
• Victory Leo

Pumas (Puma concolor)

• Pounce
• Quickswitch (partially)

Cheetahs (Acinonyx jubatus)

• Cheetor
• Cataclysm
• CatSCAN (indeterminate)

Sabertoothed cat (Smilodon sp.)

• Catilla

Odd-Toed Ungulates

Rhinos

Generation 1/Beast Era

• Headstrong
• Ramhorn
• Rhinox
• Stranglehold
• Greatshot (partially)
• Rhinobreast
• Top-Heavy

Unicron Trilogy

• Backstop
• Rhinox

Primates

Gorillas (Gorilla gorilla)

Generation 1/Beast Era

• Apeface
• Apelinq
• Beastbox
• Optimus Primal
• Primal Prime

Unicron Trilogy

• Optimus Prime

Go-Go-GoBots

• Gorillabot / Beast-Bot / Gorilla-Bot
  
  
  From Teletraan I: The Transformers Wiki, a Wikia wiki.