Some time ago, for some reason, I pondered whether, given that we have ducklings and goslings, we also have any other baby animals which end in –ling. A few days ago, I encountered bucklings, young goats. Bucks are most commonly male deer, but are first defined as the adult male of any animal. 

So are there any other baby animals which end in –ling. Yes, no, maybe … The Free Dictionary has a list of 1,915 words that end in –ling, with most being the present participle of a verb ending in –l. That obviously took some time to wade through and it’s possible/probable that I missed some. The only one I definitely knew was pigling, from Beatrix Potter’s The Tale of Pigling Bland (which I know nothing else about. Coincidently, I am working my way through the set of Potter’s stories which I bought many years ago but have never read), but piglet is much more common. Also on the list are chickling, kitling, catling, hogling, cowling (all domestic or farm animals, compare chicken, kitten, piglet and calf) and codling (a major fisheries catch). Starling is questionable. Apparently, stær meant starling, so a starling is a little starling. 

Birds can be hatchlings, fledglings, nestlings or cagelings. Mammals can be sucklings, yearlings or fatlings. Any animal or human can be a youngling, but the latter is more likely to be a youngster or child. Possibly related are princelings and lordlings, who may employ underlings and hirelings. [Added 22 Mar: I later also thought of worldling.]