This is not a SFW instance. NSFW communities will be tagged, and efforts will be made to keep SFW communities clean, but proceed at your own comfort level.
Star Trek S1E28 "The City on the Edge of Forever", Stargate SG-1 S10E6 "200", Fog effect: https://www.videezy.com/fire-and-smoke/13086-dense-smoke-going-up-creating-a-dynamic-white-texture-in-4k