Once Russia went to war with Ukraine, the ability of Russian cargo operators to continue their US business went away. Volga Dnepr had been providing a bunch of service for Boeing operations at Everett bringing in outsize airframe parts. With them out of the picture, Boeing had to find an alternative. Antonov Design Bureau designed the AN-124 originally and it has an in house airline, Antonov Airlines. They seem to have picked up a bunch of work that Volga Dnepr previously had. Despite the enthusiasm for various people calling them Russians, they are definitely Ukrainian!
They have been in and out of Paine Field pretty frequently over the last few months. I have got shots of them at different times with the aircraft carrying various messages about cities in Ukraine. Having got shots at different times, I also started shooting some video. Here are some of the shots along with a video of one of the departures.