Can the plural form of "sheep" ever be "sheeps"? [closed]
I found this Quora question which asked the same thing. The users over there agree that no, sheeps is not a word in English, even though you may have sentences like "the peoples of the world."
From the article about the plural of fish on Grammarist.com
The plural of fish is usually fish, but fishes has a few uses. In biology, for instance, fishes is used to refer to multiple species of fish.
As you can see, "fishes" is only acceptable in biology, and we can assume it is used as a technical term, rather than simply the plural of fish. As pointed out in a comment below, fish is in fact an exception, and uncountable nouns (e.g. sheep, elk) cannot have a plural.
I hope I helped you a bit.