ALLIGATOR,  BLINKER,  CATLING,  CHEEPER,  CHICKEN,  CODFISH, CODLING,  COLT,  CROCODILE,  CROW,  DONKEY,  DUCK,  DYED,  FAWN, FINGERLING,  FLAPPER,  FLEDGLING,  FROG,  GIRAFFE,  GOAT,  GORILLA,  GRILSE,  GROUSE,  GULL,  HARE,  HEIFER, 
LAMBKIN,  LEFT,  LEVERET,  LIZARD,  MACKEREL,  OCTOPUS, 
PARROT,  PARTRIDGE,  ROOSTER,  SALAMANDER,  SEAL,  SUCKLING, 
TADPOLE,  TOGO,  TRAS,  YEARLING

Animal facts:

LEVERET:  A young rabbit.  Especially one in it's first year of birth.
SUCKLING:  A very young animal or child.  Especially one not yet weaned.
FINGERLING:  A small fish, no longer than a finger. 
FLEDGLING:  A young bird just able to fly.
CODLING:  A small unripe apple.  Codling or "Codlin Moth", is also a small moth whose larvae destroy apples, pears and other fruits.
CATLING:  A little cat or kitten.

Do you see something similar in these words??  They all mean "something young" or early on in it's existence.  Even the "Codlin Moth" (also known as "Codling"), is just a larvae.  A larvae is plural for larva, which is a very young insect.

PUZZLES, PUZZLES AND MORE PUZZLES