In case of

Hej chciałem zapytać, czy takie zdanie jest poprawne:
Take some snacks in case of being hungry.
W kontekście weź jakieś przekąski na wypadek bycia głodnym.
Nauczyciel mi to wypunktował jako błędne zdanie, ale nie bardzo rozumiem czemu.

Ja bym dał you get
„of being hungry” mi wygląda na poprawne.

bo po 'in case' (na wwypadek) daje sie zdanie, a nie gerund

in the case of being hungry = 'w przypadku odczuwania glodu', ale in the case ma inne znaczenie niz in case

https://forum.wordreference.com/threads/in-case-of-gerund.539621/

Raczej you get, you are.

https://dictionary.cambridge.org/pl/grammar/british-grammar/in-case-of
Shall I keep some chicken salad for your brother in case he’s hungry when he gets here? (conjunction)

Nie mówimy przecież: I'm being hungry. - tylko - I'm hungry.

Yes, we can say “I am being hungry.”

Back to Mustang15 and “in case of”:
It is a subordinating conjunction functioning in compound sentences, and as such it is meant to join clauses: it introduces the subordinate clause. There are coordinating conjunctions in compound sentences, e.g. and, but, or,… and subordinating conjunctions in complex sentences, e.g. in case of, because, when, (as) if… Mind you, “in case of” does not mean “if.”

What can be quite perplexing, for some reason or other “in case of” is often confused with “in the case of”: “Case” in “in the case of” is a regular nominal and requires its “the.”

Sloppy minds similarly confuse “on top of” (which is legitimate for “in addition to,” because no top is implicated in that sense), and “on the top of,” in which “top” is again a nominal and needs its “the” to “present the owner of the top” mentioned. “On the top of” is functionally equivalent to the preposition “atop”: e.g., on the top of the building = atop the building.

how can a clause follow 'of' (other than a what-clause used instead of a noun)?
Why don't you edit thy post as I have done unto mine?

Maybe you do. I don't and I don't know anyone else who does.

"Being hungry" is not a type of behavior, unlike "being silly" or "sarcastic", which can happily take the present continuous.

It cannot. Copy-pasting often does that to people.