Welcome to the board, straczek1988.
The generic term for such objects is "applique." If you do a Google image search, for example, on the term "Roman applique," you'll see lots of various small, mostly bronze decorative pieces. These were attached to different objects - vessels and such - in ancient times.
I'm not saying yours is Roman - I simply don't know. It's more crude than most I've seen. But, personally, I do think it is probably ancient.