Be wary of the crows that hunt

[harry-caul]

Hello, I’m very old and forgotten how to speak welsh.
Can someone help me with a translation?

I like the phrase “helfa bran” and the word “Pwyll” So my memory tells me that maybe “pwyllog di yr helfa bran” is maybe what i’m looking for?

The phrase is a spoken as a warning, something like “Be wary of the crows that hunt”.

I’m open to alternative suggestions.
If possible I would like the phase to be informal; more slang like and dutty.

Diolch yn fawr.
Harry

[aran]

I’m afraid neither Catrin nor I have ever heard of anything like this - is it a phrase you’re trying to remember from common use, or one you’re wanting to make up? You could say ‘Byddwch wyliadwrus o’r brain ysglyfaethus’ or ‘o’r brain sy’n hela’…