There are/were several bands with the name Zyklon B. Where does it come from? Well those evil nazis released this pesticide in the gas chambers to poison and kill the Jews. So it's a pretty offensive name right? Punk of course had a lot of shock factor, but also chose names for their bands of things they were against like Police Bastard, Police Beat, Police Charged, Police Line, Police Shit. Those using the name Zyklon alert us not to ignore the past. There was a US band back in the 80's whose demo can be found at http://www.lockjaw-yappy.blogpsot/.com, a current chaos punk band from Cincinnatti, OH, a German band in the 70s with members that later were in Stress and V2.
Avoid the Polish nazi hate band with the same name. Why of all the countries would there be fascists in Poland? In WW2 over 16% of their population were killed!
A variation on the name is Zyklome A, one of greatest Belgium bands, well a great band for the whole world. They have one of my all time favourite songs "Noise and Distortion". You can download their EP from http://www.crustpunkperu.blogspot.com/. Grand Theft Audio also released a super CD by them of all their stuff from 1883, '84 & '85.
Giftgas is German for "poison gas". There is a noise band (ex-Distract) from Sweden ca1998 and a German band (see http://www.rat-shit-sandwich.blogspot.com/)
Classic Texas '77 punk band the Hugh Beaumont Experience had a song Zyklon B.