For those seeing this name for the first time. wiki says as follows:

Celtic Frost was a Swiss metal band from Zürich. They are remembered for their strong influence on the development of several varieties of extreme metal and for their avant-garde approach to music more generally.

When Fischer was asked to comment on their influence on heavy metal, he replied: “No, I try to stay away from that. I’m a musician, I don’t want to get involved with all that. It’s not healthy. I want to do good albums. I’m still alive and I feel there’s still so much in front of me. I don’t want to be bothered with who has influence and where we stand and all that. I think it’s a negative thing.”

Despite this, Celtic Frost have influenced a variety of metal bands. The band Therion, for example, took its band name from Celtic Frost’s album To Mega Therion. Other metal bands which have either cited Celtic Frost as an influence or covered Celtic Frost include: Anthrax, Obituary, Death, Benediction, Brutal Truth, Neurosis, Eyehategod, Cradle of Filth, Marduk, Dimmu Borgir, Goatwhore, Sepultura, Cancer, Asphyx, Pro-Pain, Gorgoroth, Gallhammer, Paradise Lost, Evoken, Napalm Death. Coroner, another pioneering Swiss extreme metal band, originally started off as road crew for Celtic Frost.

With that insane amount of very different bands regarding CF as an influence, it’s highly probable that your favorite metal band has Celtic Frost somewhere in their DNA. Them or Melvins, for sure. And what’s even better, I haven’t heard anything nazi-related or just bad about them since I first heard them. They are based af.