What is this magic item, an arcane focus staff with hadar’s hunger?

A month ago my character came across a magical staff with Hadar’s Hunger. I attuned to it but I still have no idea what its stats are. I don’t know what campaign we were playing, but I remember it had a Moat house, giant rats, a carrion crawler, and a basement. I stole the staff from some wizard guy(can’t remember the race) who disappeared after we beat him. I don’t know the exact D&D edition this campaign is from, I only know the campaign wasn’t from 5e since the carrion crawler stats didn’t line up with the one from my monster manual.

So, what magical item am I holding? This is actually the first time I’ve ever had a magical item, and I’m really curious as to what it is.