Here is a whole gaggle of baby animal words.
For example, a whelp is the young of a tiger, lion, wolf, bear, or dog. But it is also a modern slang term for a bratty, obstinate or overly vivacious child. There are early forms of the word appearing in Old English as hwelp, Old Norse as hvelpr, and Old High German as hwelf, and all of them seem to relate to "the young of the dog."
The word hatchling covers a lot of species. A hatchling is a young alligator, bird, reptile or fish recently emerged from an egg. It slipped into common usage in 1900, but the first documented "hatchery" for birds operated under that name in 1880. The word originates from the Old English heaccan meaning "to produce young from eggs."
Okay, a baby bird is a hatchling once it comes out of the egg, but when it's learning to fly it becomes a fledgling. We also use the word for an inexperienced person or someone newly entering a profession, such as a fledgling pilot.
The word spat refers to the young of an oyster or similar shellfish. I could not find any connection to our "spat" is also the past tense of "to spit" - though maybe those unappealing-to-me oysters look a bit like some spit! In American English, we also consider a "spat" to be a petty argument or quarrel.
A leveret is a young hare, especially one that is less than a year old. The word is a diminutive of the Norman French levre for "hare." The addition of the suffix -et denotes that the hare is young or small.
Have you heard of a polliwog? That is a a young frog or tadpole that has not yet grown legs. The word is derived from the Old English polwygle with pol meaning "head" and wygle meaning "wiggle." Idiomatically, a tadpole is a "wiggling head." In mariner slang, polliwog can also refer to a sailor who has not yet crossed the equator.
|cygnet on its mother|
A shoat is a young pig that has recently been weaned off of its mother's milk and onto solid food. Though a definitive origin of the word is unknown, "shoat" may come from the West Flemish schote referring to a pig under one year old.
A fairly common name is "kid" for a baby goat or antelope, though the word may also refer to leather made from goat hide. You might recognize the phrase, "to handle with kid gloves" meaning "to handle with care."
The first recorded usage of kid as slang for "child" was in 1599, and the verb form to kid (meaning "to joke") entered the vernacular in 1839.
A smolt is a young salmon in the midst of its first migration from fresh water into the sea. The word is of Scottish origin, though it grew to prominence in the Middle English. "Smolt" may be related to "smelt" (one of many silvery fishes that prefer cold northern waters) because salmon in this young stage resemble the smelt fish.
An eyas is a young nestling hawk or falcon. In Medieval and Renaissance Europe, hawks and falcons were esteemed hunters and the practice of training the birds was known as "falconry" or "hawking" and an eyas might have been a young bird taken from the nest for training. It is a variant of nyas from the Middle French niais meaning "nestling."
|peregrine falcon eyas|